JP4595157B2

JP4595157B2 - Ultraviolet measuring chip, ultraviolet sensor and ultraviolet measuring method

Info

Publication number: JP4595157B2
Application number: JP2000101949A
Authority: JP
Inventors: 毅西田; 英明橋本; 一芳森
Original assignee: Panasonic Corp; Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Corp; Panasonic Holdings Corp
Priority date: 2000-04-04
Filing date: 2000-04-04
Publication date: 2010-12-08
Anticipated expiration: 2020-04-04
Also published as: JP2001289708A

Description

【０００１】
【発明の属する技術分野】
本発明は、紫外線量を測定するために、全光線を受光する第１反応室と紫外線をカットした光を受光する第２反応室が設けられた紫外線測定用チップ、及びこの紫外線測定用チップを装着して電気化学的に紫外線量を算出する紫外線センサーと、さらに電気化学的に紫外線量を算出する紫外線測定方法に関する。
【０００２】
【従来の技術】
４００〜７７０ｎｍの範囲の光はいわゆる可視光線と呼ばれ、人間の目で見える光線である。このうちもっとも波長の短い４００ｎｍ付近の光は紫の光であり、この紫に近接するさらに波長の短い光を紫外線と称している。この紫外線にも３種類存在する。１つめはＵＶ−Ａ波であり、波長が３２０〜４００ｎｍで、表皮を透過して一部直接真皮まで襲う性質を有している。しわや、たるみの原因になるものである。２つめは波長が２９０〜３２０ｎｍであって、ＵＶ−Ｂ波と呼ばれ、表皮でさえぎられて、皮膚癌やしみ、ソバカスの原因になり、人間の皮膚にもっとも強い影響を与えるものである。３つめは２９０ｎｍ以下の波長を有すものでＵＶ−Ｃ波と呼ばれ、オゾン層でほとんど吸収されるが、遺伝子に影響を与え、皮膚癌を引き起こすものである。可視光線のなかでもっとも波長の長い光は７６０ｎｍ付近に存在する赤の光であって、この７６０ｎｍを超えると赤を超えた光ということで赤外線と呼ばれる。このうち７６０ｎｍ近傍の波長の短い赤外線は近赤外線と呼ばれ、波長の長い５０〜１０００μｍの赤外線は遠赤外線と呼ばれている。これは暖房などに利用され、人間にもっとも吸収され易いエネルギー波である。
【０００３】
以上説明した光の中でもっとも有害な光は紫外線である。紫外線は上述した通り皮膚に影響を及ぼすが、これには皮膚組織に病変を与えるような重大な影響はもちろん、日常発生するような軽い影響もある。すなわち、肌にあるメラノサイト（色素形成細胞）に紫外線を浴びさせるとメラニン色素を作り出し、肌が黒くなったり、シミ，ソバカスをつくってしまう。これに対し、病変を与えるような重大な影響の筆頭は、紫外線が皮膚細胞の核内にある遺伝子を傷つけ発癌させることである。通常は一部の遺伝子が傷ついても、これを治す酵素が働き修復されるが、大量の被曝で強い日焼けや傷が形成されると、酵素による修復が十分に行われなくなり、細胞が突然変異を起こし、癌を発症する可能性がきわめて高くなる。
【０００４】
ところで、近年、安定で優れた冷媒ということでずっと多用されてきたフロンガスが、十分な検討をされることなく大気内に放出されてきたため、地球の大気をつつむオゾン層が破壊されるという事態が発生している。オゾン層は地球に降り注ぐ紫外線を遮断し生物を守る重要な役割を果たしているが、このオゾン層が破壊されたため地表に届く紫外線の量が増加し、皮膚癌が多発し、生物に大きな影響が出るようになってきている。日本国内での皮膚癌の発症率は、１９６０年，１９７０年代には約１０万人に１人の割合であったが、現在は約１０万人当り５人程度に増えている。ただ、この割合は、豪州の１０万人当り８００人、米国の１０万人当り２５０人といった割合に比べると格段に少ないが、確実に増えてきているといえる。そして、オゾンが１％減少すると紫外線は２％増加し、皮膚癌患者は３〜５％程度増えるという報告もある（市橋正光、“医療ルネッサンス”、読売新聞、［ｏｎｌｉｎｅ］、（平成１２年３月３日検索）、＜ＵＲＬ：ｈｔｔｐ／／ｗｗｗ３．ｙｏｍｉｕｒｉ．ｃｏ．ｊｐ／ｍｅｄｉｃａｓｌ／ｌｉｆｅ／９６１１２９０１．ｈｔｍ＞）。
【０００５】
ところで、全国の２４大学病院を対象に、１９７０年代と１９８０年代の皮膚科外来患者のうち、皮膚癌患者の占める割合が調査された。この２つの年代を比較すると、１９８０年代の皮膚癌患者の方が、表皮の最下層に並ぶ基底細胞癌で１７％増加し、皮膚の前癌症状で、肌に赤や黒のまだらやただれができる日光角化症が８４％増加したという報告がなされている。従って、子供等が日中に屋外で思いっきり遊ぶことは成長のための重要なファクターであるが、スポーツやレクリエーション等で長時間遊んで日光を多量に浴びる場合逆効果で、長そでシャツを着たり、日焼け止めのクリームを塗る等の紫外線対策が必要なことが分かる。とくに、ごく少量の紫外線でも極度の日焼けを起こす色素性乾皮症患者は、紫外線障害を受けた遺伝子を修復する酵素システムに遺伝的欠陥があるため、通常人の１０００倍から２０００倍も発癌するおそれがあり、紫外線対策はとくに念入りに行われなければならない。
【０００６】
この紫外線対策がいかに重要かということを示す実験が神戸大学の市橋正光教授によって行われている。実験というのは、色素性乾皮症に罹った４歳と２歳の姉妹の患者に、日焼け止めクリームを塗ること、帽子を被ることなどの紫外線対策を徹底的に指導し、その後の紫外線の影響を遮断することで、それまで無防備に過ごした２人の２年の差がどれだけ発癌に影響するかということを追跡したものである。結果として２人はいずれも発癌したが、姉は１３歳で発癌し、妹は２３歳で発癌するに至った。すなわち、姉は幼児時代に紫外線を無防備に２年間多く浴びたために、１０年も早く発癌したことになる。紫外線からの保護がいかに重要かがを示す事実である。しかも、紫外線は皮膚の免疫機構にも悪影響を与える。動物実験では、紫外線照射で全身の免疫力が低下し、感染症に罹りやすくなることが実証されている。
【０００７】
免疫力が低下すると、癌細胞が発生してもこれを排除することができない。米国のある研究では、皮膚がうっすらと赤くなる程度の紫外線量を基準にして、これの４倍程度の紫外線を浴びた場合、普通の人で４０％、皮膚癌患者は９５％の人が免疫力が正常にはたらかなかったと報告されている。
【０００８】
ところで、欧米では一般に日焼けは危険であるとの意識が浸透しているが、日本の皮膚癌患者は高齢者が大半であって、発病するまでに若年の人間より時間がかかることが多く、一般に日本では紫外線に対する認識が甘いといわれている。しかし、オゾン層が破壊され始めている現代、自分たちには無関係なことと悠長に構えている訳にはいかない。
【０００９】
このオゾン層は、地球に降り注ぐ強い紫外線の作用で成層圏の酸素（Ｏ₂）がオゾン（Ｏ₃）に変化させられ、濃度を高めた大気の層である。このような反応が起こることで太陽の光に含まれている有害なＵＶ−Ｃ等の紫外線をカットし、地表の生物の生命を守っている。しかし、既に述べたように、この二、三十年間、冷媒や、半導体等の洗浄液としてフロンガスが多用され、しかも、それが環境への影響を十分検討することなく大気中に放出され続けてきたため、フロンガス中の塩素が成層圏において紫外線を受けて遊離し、これがオゾン層のオゾンと反応して、さらに酸素とＣＬＯに分解するようになったからだといわれている。このようにしてオゾンの濃度が低下すると、オゾン層にはもう有害な紫外線を遮断する力がなく、紫外線はそのまま日常的に地表にまで到達し、生物は知らず知らずのうちに多量の紫外線を浴び、生命維持に大きな影響がでることになった。
【００１０】
従って、日常生活の中でどれくらい紫外線を浴びているのか、その受光量を実測する必要性が今ほど高まったことはかってない。こうした事態を受けて、環境庁と気象庁も１９９３年から東京で紫外線のモニタリングを開始している。しかし、従来紫外線測定のための測定装置は数少ないものであった。
【００１１】
そこで、従来の紫外線測定装置にどのような装置があったかについて説明する。その代表的なものにブリューワ分光光度計がある。このブリューワ分光光度計は、ＵＶ−Ｂ紫外線を０．５ｎｍ刻みの波長で高精度に分光観測できる特性をもつものである。しかし、ブリューワ分光光度計は少し安定性に欠け、厳密な保守管理を行わなければならないものである。また、このほかの紫外線測定装置として、太陽光にさらしたとき色が徐々に白から青に変化していくＵＶセンサーがある。色の変化を見て紫外線量を判断するものである。この他、電気科学的に紫外線を測定する紫外線強度センサーもある（特開平９−３０４１７７号公報）。この紫外線強度センサーは、光照射部にその一端が設置される石英ファイバーをもち、この石英ファイバーによって導かれた光から紫外線成分だけを取り出すＵＶバンドパスフィルターと、この紫外線成分の強度を測定する光強度センサーが設けられた側光部を備えており、この側光部からの紫外線強度信号に基づいて紫外線強度を表示する表示部を備えた強度計本体から構成されている。
【００１２】
【発明が解決しようとする課題】
ところが、従来のブリューワ分光光度計は、高精度ではあるが、やや安定性に欠けるため厳密な保守管理が要求され、点検や較正をきわめて頻繁に行わなければならないものであった。その上、コストが高く、持ち運びできないものであり、専門家でなければ使いこなせず、一般人が日常浴びる照射量を測るのに適した測定装置とはいえないものであった。
【００１３】
次に、ＵＶセンサーは、単純な色変化を見て判断するため精度が悪く、とくに個人的な感覚に依存するため測定結果の評価に個人差が大きいという問題があった。
【００１４】
さらに、従来の紫外線強度センサーでは、その時点、時点の強度しか計れず、一日通して浴びた累積した紫外線量を測ることはできないものであった。同時に、このセンサーは構造も複雑で、持ち運びするのが困難なものであった。
【００１５】
そこで、このような問題点を解決するために本発明は、小量の試薬で測定でき、コンパクトで扱い易く、受光時間の長さによらず、精度の高い紫外線量を測定できる紫外線測定用チップを提供することを目的とする。
【００１６】
また、本発明は、小量の試薬で測定でき、コンパクトかつ簡単に操作でき、持ち運びが容易で、受光時間の長さによらず、精度の高い紫外線量を測定する紫外線センサーを提供することを目的とする。
【００１７】
そして、本発明は、小量の試薬で、簡単に測定でき、受光時間の長さによらず、精度が高い紫外線量を測定できる紫外線測定方法を提供することを目的とする。
【００１８】
【課題を解決するための手段】
上記課題を解決するため本発明の紫外線測定用チップは、全光線受光量検出部と紫外線カット受光量検出部とを備えた紫外線測定用チップであって、前記全光線受光量検出部には、キノン，有機溶媒，電解質含有の共存電解液を収容し、第１光透過窓が設けられた第１反応室と、前記第１光透過窓に設けられた全光線透過板と、前記第１反応室内に配設され、且つ前記共存電解液に浸漬される第１作用電極と第１対極と第１比較電極が設けられ、前記紫外線カット受光量検出部には、キノン，有機溶媒，電解質含有の共存電解液を収容し、第２光透過窓が設けられた第２反応室と、前記第２光透過窓に設けられた紫外線カット透過板と、前記第２反応室内に配設され、且つ前記共存電解液に浸漬される第２作用電極と第２対極と第２比較電極が設けられており、前記第１作用電極，前記第１対極，前記第１比較電極，前記第２作用電極，前記第２対極，前記第２比較電極とそれぞれ電気的に接続された複数の端子を備えていることを特徴とする。
【００１９】
これにより、小量の試薬で測定でき、コンパクトで扱い易く、受光時間の長さによらず、精度の高い紫外線量を測定できる。
【００２０】
また、本発明の紫外線センサーは、上記の紫外線測定用チップを挿入し、前記端子のそれぞれと電気的に接続できるコネクタ端子が設けられた測定用チップ挿入部を備え、前記紫外線測定用チップを挿入したとき前記第１作用電極と前記第１対極間に電圧を印加できる第１電源と、前記第２作用電極と前記第２対極間に電圧を印加できる第２電源とを有し、前記第１作用電極と前記第１比較電極間の電位を掃引するとともに、前記第２作用電極と前記第２比較電極間の電位を掃引する制御部と、前記第１作用電極と前記第１対極間に流れる電流を検知する第１検出部と、前記第２作用電極と前記第２対極間に流れる電流を検知する第２検出部とを有し、前記第１検出部と前記第２検出部で検知された電流値の差から紫外線量を算出する演算部を備えたことを特徴とする。
【００２１】
これにより、小量の試薬で測定でき、コンパクトかつ簡単に操作でき、持ち運びが容易で、受光時間の長さによらず、精度の高い紫外線量を測定することができる。
【００２２】
さらに、本発明の紫外線測定方法は、キノン，有機溶媒，電解質含有の共存電解液に全光線を照射するとともに、キノン，有機溶媒，電解質含有の共存電解液に紫外線をカットした光を照射し、全光線を照射した共存電解液と紫外線をカットした光を照射した共存電解液をそれぞれボルタンメトリーし、還元電流値の差をとることにより紫外線量を算出することを特徴とする。
【００２３】
これにより、小量の試薬で、簡単に測定でき、受光時間の長さによらず、精度が高い紫外線量を測定できる。
【００２４】
【発明の実施の形態】
本発明に係る紫外線測定用チップは、全光線受光量検出部と紫外線カット受光量検出部とを備えた紫外線測定用チップであって、前記全光線受光量検出部には、キノン，有機溶媒，電解質含有の共存電解液を収容し、第１光透過窓が設けられた第１反応室と、前記第１光透過窓に設けられた全光線透過板と、前記第１反応室内に配設され、且つ前記共存電解液に浸漬される第１作用電極と第１対極と第１比較電極が設けられ、前記紫外線カット受光量検出部には、キノン，有機溶媒，電解質含有の共存電解液を収容し、第２光透過窓が設けられた第２反応室と、前記第２光透過窓に設けられた紫外線カット透過板と、前記第２反応室内に配設され、且つ前記共存電解液に浸漬される第２作用電極と第２対極と第２比較電極が設けられており、前記第１作用電極，前記第１対極，前記第１比較電極，前記第２作用電極，前記第２対極，前記第２比較電極とそれぞれ電気的に接続された複数の端子を備えていることを特徴とする紫外線測定用チップであるから、小量の試薬で測定でき、コンパクトかつ簡単に操作でき、持ち運びが容易で、受光時間の長さによらず、精度の高い紫外線量を測定することができる。
【００２５】
さらに本発明に係る紫外線測定用チップは、前記全光線透過板が石英ガラスを含んでいることを特徴とする紫外線測定用チップであるから、他の周波数の光を遮断することなく、紫外線を９９％以上透過させ、安価である。
【００２６】
さらに本発明に係る紫外線測定用チップは、前記紫外線カット透過板が紫外線カットフィルターを備えたことを特徴とする紫外線測定用チップであるから、他の周波数の光を遮断することなく、紫外線のみをカットできる。
【００２７】
さらに本発明に係る紫外線測定用チップは、前記第１作用電極と第２作用電極がそれぞれ炭素，ガラス状炭素，金の中から選ばれた１以上の材料から構成されていることを特徴とする紫外線測定用チップであるから、電流値を安定して測定できる。
【００２８】
さらに本発明に係る紫外線測定用チップは、前記第１対極と前記第２対極がそれぞれ耐食性導電体から構成されていることを特徴とする紫外線測定用チップであるから、劣化もなく、安定して測定できる。
【００２９】
さらに本発明に係る紫外線測定用チップは、前記耐食性導電体が白金，ステンレス，白金含有合金，炭素の中から選ばれた１以上の材料から構成されていることを特徴とする紫外線測定用チップであるから、劣化がほとんどなく、安定した測定ができる。
【００３０】
さらに本発明に係る紫外線測定用チップは、前記第１比較電極と前記第２比較電極がそれぞれ金または炭素から構成されていることを特徴とする紫外線測定用チップであるから、比較電極が単純で安価になる。
【００３１】
また本発明に係る紫外線センサーは、上記の紫外線測定用チップを挿入し、前記端子のそれぞれと電気的に接続できるコネクタ端子が設けられた測定用チップ挿入部を備え、前記紫外線測定用チップを挿入したとき前記第１作用電極と前記第１対極間に電圧を印加できる第１電源と、前記第２作用電極と前記第２対極間に電圧を印加できる第２電源とを有し、前記第１作用電極と前記第１比較電極間の電位を掃引するとともに、前記第２作用電極と前記第２比較電極間の電位を掃引する制御部と、前記第１作用電極と前記第１対極間に流れる電流を検知する第１検出部と、前記第２作用電極と前記第２対極間に流れる電流を検知する第２検出部とを有し、前記第１検出部と前記第２検出部で検知された電流値の差から紫外線量を算出する演算部を備えたことを特徴とする紫外線センサーであるから、小量の試薬で測定でき、コンパクトかつ簡単に操作でき、持ち運びが容易で、受光時間の長さによらず、精度の高い紫外線量を測定することができる。
【００３２】
また本発明に係る紫外線センサーは、上記の紫外線測定用チップを挿入し、前記端子のそれぞれと電気的に接続できるコネクタ端子が設けられた測定用チップ挿入部を備え、前記紫外線測定用チップを挿入したとき前記第１作用電極と前記第１対極間に電圧を印加できる第１電源と、前記第２作用電極と前記第２対極間に電圧を印加できる第２電源とを有し、前記第１作用電極と前記第１比較電極間を前記第１比較電極を基準にして所定の電位に制御するとともに、前記第２作用電極と前記第２比較電極間を前記第２比較電極を基準にして所定の電位に制御する制御部と、前記第１作用電極と前記第１対極間に流れる電流を検知する第１検出部と、前記第２作用電極と前記第２対極間に流れる電流を検知する第２検出部とを有し、前記第１検出部と前記第２検出部で検知された電流値の差から紫外線量を算出する演算部を備えたことを特徴とする紫外線センサーであるから、小量の試薬で測定でき、コンパクトかつ簡単に操作でき、制御部がより簡単であり、持ち運びが容易で、受光時間の長さによらず、精度の高い紫外線量を測定することができる。
【００３３】
さらに本発明に係る紫外線センサーは、前記第２電源が前記第１電源であることを特徴とする紫外線センサーであるから、電源回路がコンパクトになる。
【００３４】
さらに本発明に係る紫外線センサーは、前記制御部が１０ｍＶ／ｓ〜２００ｍＶ／ｓの掃引速度で掃引することを特徴とする紫外線センサーであるから、電流のプレピーク値を精度良く測定できる。
【００３５】
また本発明に係る紫外線測定方法は、キノン，有機溶媒，電解質含有の共存電解液に全光線を照射するとともに、キノン，有機溶媒，電解質含有の共存電解液に紫外線をカットした光を照射し、全光線を照射した共存電解液と紫外線をカットした光を照射した共存電解液をそれぞれボルタンメトリーし、還元電流値の差をとることにより紫外線量を算出することを特徴とする紫外線測定方法であるから、小量の試薬で、簡単に測定でき、精度が高い紫外線量を測定できる。
【００３６】
また本発明に係る紫外線測定方法は、キノン，有機溶媒，電解質含有の共存電解液に全光線を照射するとともに、キノン，有機溶媒，電解質含有の共存電解液に紫外線をカットした光を照射し、全光線を照射した共存電解液と紫外線をカットした光を照射した共存電解液をそれぞれクロノアンペロメトリーし、還元電流値の差をとることにより紫外線量を算出することを特徴とする紫外線測定方法であるから、小量の試薬で、さらに簡単且つ迅速に測定でき、精度が高い紫外線量を測定できる。
【００３７】
以下、本発明の実施の形態について図１〜図６を用いて説明する。
【００３８】
（実施の形態１）
まず、本発明の一実施の形態である紫外線センサーと紫外線測定用チップについて、図面に基づいて詳細に説明する。図１は本発明の実施の形態１における紫外線センサーの概略外観図である。図１において、１は本体、２は測定値を紫外線量に換算して表示する表示部、３は測定を開始するためのスタート・ストップボタン、４は記憶データを呼び出したり各種モードを切り替えるモード切り替えボタン、５は電源を入切する電源ボタン、６は後述する紫外線測定用チップ（以下、測定チップ）Ｃによって紫外線を受光した後、この測定チップＣを挿入して電気的接続を行い紫外線量を測定する測定チップ挿入部である。測定チップ挿入部６の内部には、測定チップＣの端子と接続が可能なコネクタ端子（図示しない）が設けられている。
【００３９】
図２は本発明の実施の形態１における紫外線センサーの紫外線測定用チップの説明図である。７は第１作用電極用パターン、７′は第２作用電極用パターン、８は第１対極用パターン、８′は第２対極用パターン、９は第１比較電極用パターン、９′は第２比較電極用パターン、１０は第１作用電極、１０′は第２作用電極、１１は第１対極、１１′は第２対極、１２は第１比較電極、１２′は第２比較電極である。７ｔ1は第１作用電極用の端子、７ｔ2は第２作用電極用の端子、８ｔ1は第１対極用の端子、８ｔ2は第２対極用の端子、９ｔ1は第１比較電極用の端子、９ｔ2は第２比較電極用の端子である。１５は基板である。
【００４０】
第１作用電極用パターン７は、樹脂バインダーを含有させた通電性カーボンペーストを基板１５にスクリーン印刷で薄く帯状に印刷して薄膜化したものである。第１作用電極用パターン７は第１作用電極１０に接続される。第１作用電極１０は、グラッシーカーボンと呼ばれる炭素電極，ＰＦＣと呼ばれるプラスチックフォームを１０００℃〜２０００℃で焼結した炭素材料、あるいは金を蒸着またはスパッタリングなどして形成した薄膜で構成される。第２作用電極１０′もまったく同様に構成するのが適当である。しかし、このように第１作用電極１０と第１作用電極用パターン７を別材料で構成するのでなく、第１作用電極用パターン７といっしょに通電性カーボンペーストでスクリーン印刷して薄膜として一体成形するのが、工程を減らし、コストを低減できて望ましい。第２作用電極１０′に関しても第１作用電極１０と同様に一体成形するのが適当である。
【００４１】
次に、第１対極用パターン８は、樹脂バインダーを含有させた通電性カーボンペーストを基板１５にスクリーン印刷で薄く帯状に印刷して薄膜化したものである。第１対極用パターン８は第１対極１１に接続される。第１対極１１は白金，黒鉛，金，ステンレス，アルミニウムその他の導電性材料から構成される。第２対極１１′もまったく同様に構成するのが適当である。第１作用電極１０と第１作用電極用パターン７との関係と同様に、第１対極１１も第１対極用パターン８と別材料で構成するのでなく、第１対極用パターン８といっしょに通電性カーボンペーストで一体形成するのが、工程が減り、コストも低減されるので適当である。第２対極１１′に関しても第１対極１１と同様に一体成形するのが適当である。
【００４２】
さらに、第１比較電極用パターン９は、樹脂バインダーを含有させた通電性カーボンペーストを基板１５にスクリーン印刷で薄く帯状に印刷して薄膜化したものである。第１比較電極パターン９は第１比較電極１２に接続される。この第１比較電極１２はグラッシーカーボンと呼ばれる炭素電極，ＰＦＣと呼ばれるプラスチックフォームを１０００℃〜２０００℃で焼結した炭素材料、あるいは金を蒸着またはスパッタリングなどして形成した薄膜で構成される。これらは第２比較電極用パターン９′と第２比較電極１２′でも同様である。
【００４３】
なお、第１作用電極用の端子７ｔ1、第１対極用の端子８ｔ1、第１比較電極用の端子９ｔ1、第２作用電極用の端子７ｔ2、第２対極用の端子８ｔ2、第２比較電極用の端子９ｔ2を、白金，金，ステンレスその他の導電性材料でつくって強化しておくのが、コネクタの接触強度を高め、電気的にも抵抗少ない接続が可能になり、望ましい。
【００４４】
続いて、図２において、１３は第１光透過窓、１３′は第２光透過窓、１４は第１反応室、１４′は第２反応室、１６は全光線透過板、１６′は紫外線カット透過板である。第１反応室１４の表面には全光線を透過する第１光透過窓１３が開口され、この第１光透過窓１３には全光線透過板１６が取り付けられている。同じく、第２反応室１４′の表面には紫外線だけをカットした光が透過する第２光透過窓１３′が開口され、この第２光透過窓１３に紫外線カット透過板１６′が取り付けられている。
【００４５】
この第１反応室１４内には、第１作用電極１０、第１対極１１、第１比較電極１２が互いに非接触の状態で並べられ、それぞれが第１作用電極用パターン７、第１対極用パターン８、第１比較電極用パターン９によって外部に導き出される。この導き出された第１作用電極用パターン７、第１対極用パターン８、第１比較電極用パターン９の端部は、第１作用電極用の端子７ｔ1、第１対極用の端子８ｔ1、第１比較電極用の端子９ｔ1となっており、測定チップ挿入部６に装着されたとき電気的に接続される。第１作用電極１０、第１対極１１、第１比較電極１２の各電極部分と、第１作用電極用の端子７ｔ1、第１対極用の端子８ｔ1、第１比較電極用の端子９ｔ1の各端子部分を除き、第１作用電極用パターン７、第１対極用パターン８、第１比較電極用パターン９の表面は絶縁材料で被覆されている。
【００４６】
同様に、第２反応室１４′内には、第２作用電極１０′、第２対極１１′、第２比較電極１２′が互いに非接触の状態で並べられ、それぞれが第２作用電極用パターン７′、第２対極用パターン８′、第２比較電極用パターン９′によって外部に導き出される。この導き出された第２作用電極用パターン７′、第２対極用パターン８′、第２比較電極用パターン９′の端部は、第２作用電極用の端子７ｔ2、第２対極用の端子８ｔ2、第２比較電極用の端子９ｔ2となっており、測定チップ挿入部６に装着されたとき電気的に接続される。第２作用電極１０′、第２対極１１′、第２比較電極１２′の各電極部分と、第２作用電極用の端子７ｔ2、第２対極用の端子８ｔ2、第２比較電極用の端子９ｔ2の各端子部分を除き、第２作用電極用パターン７′、第２対極用パターン８′、第２比較電極用パターン９′の表面は絶縁材料で被覆されている。
【００４７】
そして、本実施の形態１においては、第１作用電極用パターン７、第１対極用パターン８、第１比較電極用パターン９、第２作用電極用パターン７′、第２対極用パターン８′、第２比較電極用パターン９′はいずれも平行に引き出されており、端部となる第１作用電極用の端子７ｔ1、第１対極用の端子８ｔ1、第１比較電極用の端子９ｔ1、第２作用電極用の端子７ｔ2、第２対極用の端子８ｔ2、第２比較電極用の端子９ｔ2も略等ピッチで平行に設けられている。これによりコンパクト化が可能で、測定用チップ挿入部６内のコネクタ端子と電気的に接続される。
【００４８】
ところで、本実施の形態１の第１反応室１４と第２反応室１４′内には、光の受光量を電気化学的に測定するための共存電解液Ａと共存電解液Ａ′がそれぞれ収容されている。この共存電解液Ａと共存電解液Ａ′は同一成分であり、いずれもキノンをエタノールやイソプロピルアルコールなどの有機溶媒に溶解したもので、さらに塩化ナトリウムや塩化リチウムなどの電解質を添加している。使用されるキノンの例をあげると、ｐ−ベンゾキノン，３−メチル−ｐ−ベンゾキノン、ｏ−ベンゾキノン、ジフェノキノン、ナフトキノン、アントラキノン、ベンゼンアゾヒドロキノン、さらにこれらキノンの誘導体等がある。キノン類まで含むものである。実施の形態１においては、共存電解液Ａ，Ａ′の組成として、具体的には３−メチル−ｐ−ベンゾキノン２０ｍＭと、塩化ナトリウム１５０ｍＭを、エタノールと水の混合比率８対２の溶媒に溶解して作製したものを利用している。
【００４９】
共存電解液Ａが収容される第１反応室１４には全光線透過板１６が取り付けられている。この全光線透過板１６は紫外線透過率９９％の石英ガラス、ダイヤモンド、塩化ナトリウム単結晶、チタニアなどが適当である。また、共存電解液Ａ′が収容される第２反応室１４′には紫外線カット透過板１６′が取り付けられている。この紫外線カット透過板１６′は紫外線を９０％以上遮断し、赤外線等の他の光線は透過させる透明の塩化ビニール樹脂、アクリル樹脂、ポリカーボネート樹脂、メタクリル樹脂等の樹脂か、もしくは通常のガラスの表面に軟質ビニールフィルム、ポリウレタンフィルム、ポリエステルフィルムなどの特殊処理を施した紫外線カットフィルターを施したものである。
【００５０】
このように、第１反応室１４には、第１光透過窓１３が設けられ、さらに全光線透過板１６が嵌め込まれており、内部に共存電解液Ａが収容されている。そして、この共存電解液Ａには第１作用電極１０、第１対極１１、第１比較電極１２が非接触の状態で浸漬されている。これらで本実施の形態１の測定チップＣの全光線受光量検出部Ａを構成している。また、第２反応室１４′には、第２光透過窓１３′が設けられ、さらに紫外線カット透過板１６′が嵌め込まれており、内部に共存電解液Ａ′が収容されている。そして、この共存電解液Ａ′には第２作用電極１０′、第２対極１１′、第２較電極１２′が非接触の状態で浸漬されている。これらで本実施の形態１の測定チップＣの紫外線カット受光量検出部Ｂを構成している。
【００５１】
なお、測定チップＣは、紫外線の影響を除いてキノンへの影響を同一にするため、全光線受光量検出部Ａと紫外線カット受光量検出部Ｂを接近させ、２つ極近傍に並べて設けてある。共存電解液Ａ，Ａ′は紫外線を除いてキノンの劣化度を共通にするため、全光線受光量検出部Ａと紫外線カット受光量検出部Ｂとを構成する電極材料、電極用パターン材料等を同一にし、且つ同じ成分で環境が同一条件の共存電解液を用いるのが適当である。
【００５２】
次いで、本実施の形態１の測定チップＣで紫外線量を検出できる理由を以下説明する。図３は、キノン含有の共存電解液への光の照射時間とキノン還元電流のピーク値の関係を示すグラフである。キノンは３−メチル−ｐ−ベンゾキノンで、照射した光は３０Ｗ／ｍ²の紫外線と全光線に当る日光である。このときの測定条件は、作用電極と比較電極はグラッシーカーボン、対極は白金で構成し、作用電極の面積３．２ｍｍ²、共存電解液は３−メチル−ｐ−ベンゾキノン２０ｍＭ、塩化ナトリウム１５０ｍＭ、エタノールと水の混合比率８：２を混合したものであり、比較電極電位を基準に作用電極が掃引電位となるように作用電極と対極間に電圧を印加し、掃引速度１００ｍＶ／秒で掃引して３−メチル−ｐ−ベンゾキノンの還元電位においてピークをもつ還元電流を得たものである。なお、後述するように、掃引するのでなく所定の電圧を印加してファラデー電流を測定して還元電流値を得るのでもよい。図３に示すとおり、紫外線を受光した場合も、日光をすべて受光した場合も、受光時間が増加するとキノン還元電流のピーク値は低下していく。従って、予め強度が分かっている紫外線を測定チップに照射して、これによって３−メチル−ｐ−ベンゾキノンを減少させた共存電解液を電気化学的に測定し、受光時間と紫外線の強度を変量にして、検量線を作成しておけば、３−メチル−ｐ−ベンゾキノンの量を測定するだけで測定チップが受光した紫外線の量を測定できることになる。
【００５３】
しかし、キノンの劣化に影響を及ぼすのは光ばかりではない。周囲の温度など、光以外の因子もキノンの劣化に大きな影響を与える。そこで、本発明においては、上述したとおり紫外線だけを遮断した共存電解液と、紫外線を遮断せず残りのすべてにおいて同一の条件を与えた共存電解液をシリアルに２つほぼ同時に測定するようにしている。紫外線以外では両者全く同一の条件であるから、キノンの量を２つの共存電解液で測定すれば、紫外線を当てた側の共存電解液において余分に減少したキノンの量が紫外線の受光量に比例していることになる。このように、紫外線を遮断して測定した共存電解液と、すべての光を透過させて測定した共存電解液の差をとって、紫外線の影響によるキノンの減少量を求め、予め測定しておいた紫外線の検量線と比較することで、紫外線の受光量を検出できるものである。なお、以上説明したことから分かるとおり、本発明の紫外線測定方法によれば紫外線の受光量が時間に比例して正確に測定できるため、従来のブリューワ分光光度計ができなかった１日分の紫外線の受光量といった長時間の受光量を正確に測定できる特徴がある。
【００５４】
ところで、紫外線が紫外線カット透過板１６′によってどの程度遮断されるかは、紫外線カット透過板１６′の材質による。そこで遮断率が低い材質の場合は、この紫外線カット透過板１６′で紫外線を遮断した場合と全光線透過板１６でこれを透過させた場合の還元電流値の差をとり、遮断率、すなわち紫外線カット透過板１６′の材質に応じ、１００％遮断した場合に換算するのが適当である。
【００５５】
本実施の形態１においては、全光線受光量検出部Ａと紫外線カット受光量検出部Ｂの共存電解液Ａ，Ａ′は上述した同一成分の溶液を使用し、キノンとして３−メチル−ｐ−ベンゾキノンを採用しており、全光線受光量検出部Ａでは、表面に設けられた全光線透過板１６が紫外線を含む全光線を透過するため、透過した紫外線によって３−メチル−ｐ−ハイドロキシベンゾキノンとなって３−メチル−ｐ−ベンゾキノンの量が減少する。これとともに、他の光線（例えば赤外線など）や周囲の温度等によっても同様の変化を起こしてさらにその量を減らす。これに対し、紫外線カット受光量検出部Ｂでは、紫外線カット透過板１６′が紫外線をカットするため、３−メチル−ｐ−ベンゾキノンに対する紫外線の影響が断たれ、３−メチル−ｐ−ベンゾキノンは紫外線以外の条件の影響で３−メチル−ｐ−ハイドロキシベンゾキノンに変化して減少する。すなわち、両者の差は紫外線による３−メチル−ｐ−ベンゾキノンの減少のみとなる。
【００５６】
３−メチル−ｐ−ベンゾキノンが減少すると、第１作用電極１０と第２作用電極１０′に３−メチル−ｐ−ベンゾキノンの還元電位を印加したとき、第１作用電極１０と第２作用電極１０′近傍で３−メチル−ｐ−ベンゾキノンがプロトンを奪って流れる還元電流がそれぞれ減少する。全光線受光量検出部Ａと紫外線カット受光量検出部Ｂで測定した３−メチル−ｐ−ベンゾキノンの還元電流値の差を算出すれば、この差は紫外線由来の還元電流値の差となる。そして、紫外線を受光する時間と、紫外線の強度ごとに予め検量しておいた３−メチル−ｐ−ベンゾキノンの減少量を示す検量線との比較を行うことで紫外線の受光量を測定するものである。もし、紫外線カット透過板１６′が１００％紫外線をカットできない場合は、紫外線カット透過板１６′の遮断率に応じて補正する。例えば、９０％の遮断率なら１．０３倍する。
【００５７】
ところで、本実施の形態１においては、還元電流を測定するために第１作用電極１０と第２作用電極１０′の電位を掃引している。しかし、掃引する以外の別のタイプの電圧印加方法も有効である。そこで、掃引する方法を含め、この２つの印加方法についてもう少し詳細に説明する。
【００５８】
１つめの印加方法は、既に述べ実施の形態１でも使用した方法で、第１対極１１または第２対極１１′を、第１比較電極１２または第２比較電極１２′に対して、例えば＋８００ｍＶ〜−１０００ｍＶの範囲で掃引する方法である。掃引する電圧範囲は溶存酸素の影響を受けないようにするために選択されたものであるが、各電極の種類やキノンの種類によっても変化するので注意が必要である。この方法はボルタンメトリーと呼ばれる。図４はボルタンメトリーを行ったときに現れる還元電流の説明図である。図４に示すように、ボルタンメトリーした場合、掃引の結果得られた電位−還元電流曲線（ボルタモグラム）の中に現れる還元電流のピーク値を測定する。なお、掃引速度としては電極反応を電子移動律速とするために１０ｍＶ／ｓ〜２００ｍＶ／ｓとするのが適当である。
【００５９】
２つめの印加方法は、第１対極１１または第２対極１１′を、第１比較電極１２または第２比較電極１２′に対して３−メチル−ｐ−ベンゾキノンの還元電位をパルス状またはステップ状に印加する方法である。キノンの種類にもよるが、おおむね紫外線の吸収との関係から−２００ｍＶ〜−１０００ｍＶの範囲となるようなキノンを選ぶのが適当である。この電圧範囲は溶存酸素の影響を受けない範囲である。なお、第１作用電極１０または第２作用電極１０′が上記したような炭素材料とは別の材料になるとこの範囲は若干変動する。この印加方法はクロノアンペロメトリーと呼ばれる。クロノアンペロメトリーを行うと、第１作用電極１０または第２作用電極１０′表面に電気二重層が形成され、電極近傍でキノンがアニオン化して溶媒よりプロトンを奪う現象が発生する。本実施の形態１では３−メチル−ｐ−ベンゾキノンが用いられているから、電子の移動により還元され、ヒドロ化して３−メチル−ｐ−ヒドロキシベンゾキノンとなる。このとき急激に流れる還元電流はファラデー電流と呼ばれ、これが３−メチル−ｐ−ベンゾキノンの量に比例するから、このファラデー電流値を測定することで逆に３−メチル−ｐ−ベンゾキノンの量が測定できるものである。図５はクロノアンペロメトリーを行ったときに現れるファラデー電流の説明図である。
【００６０】
本実施の形態１における紫外線センサーと測定チップは、以上説明した電気化学的方法で還元電流値の測定を行って、紫外線の量を算出し、表示部に紫外線照射量を表示するものであるが、その具体的な制御回路と操作について説明する。
【００６１】
まず、紫外線受光量を測定するため測定チップＣを身体の一部に取り付け、全光線受光量検出部Ａの第１光透過窓１３と紫外線カット受光量検出部Ｂの第２光透過窓１３′を太陽の方向に向けるようにする。一定時間日光を浴びた後、測定チップＣを身体から取り外し、本体１の測定チップ挿入部６に挿入する。これにより各電極と本体１内の制御回路が電気的に接続される。そこで、電源ボタン５を押して、紫外線センサーを起動させる。さらに、測定を開始するためにスタートボタン３を押す。図６は本実施の形態１における紫外線センサーの制御回路図である。図６において、３５は表示部２の１つであるＬＣＤ、３６は紫外線センサーを制御する制御部であって、マイクロコンピューターから構成され、メモリを備えている。制御部３６は測定チップＣの各電極に所定の電位を与える制御を行うとともにＬＣＤ３５も制御し、後述の演算部４８に全光線受光量検出部Ａと紫外線カット受光量検出部Ｂのそれぞれで測定された還元電流のピーク値から紫外線量を算出させるものである。
【００６２】
スタートボタン３と電源ボタン５が押されたら、制御部３６は対応する回路内のスイッチをＯＮし、紫外線センサーは動作可能になる。そして、制御部３６はまず全光線受光量検出部Ａに受光量の検出を開始させ、これが終了した時点に、紫外線カット受光量検出部Ｂに紫外線がカットされた光の受光量を検出するように指令する。
【００６３】
３７は第１比較電極１２，第２比較電極１２′や、第１対極１１，第２対極１１′に所定の電位を印加するために制御部３６が出力したデータをアナログ信号に変換するＤ／Ａコンバーター、３８は第１対極１１または第２対極１１′に所定の電位を印加するオペアンプ、３９は第１比較電極１２と第２比較電極１２′への出力を切り替えるリレー、４０は第１対極１１と第２対極１１′への出力を切り替えるリレーである。また、４１は第１作用電極１０，第２作用電極１０′に還元電流を測定するための所定の電位を印加するために制御部３６が出力したデータをアナログ信号に変換するＤ／Ａコンバーター、４３は第１作用電極１０，第２作用電極１０′に還元電流を測定するための所定の電位を印加するオペアンプ、４４は第１作用電極１０と第１対極１１間，第２作用電極１０′と第２対極１１′間を流れる電流を測定するための抵抗、４５は第１作用電極１０と第２作用電極１０′とを切り替えるためのリレーである。４６は抵抗４４の両端で発生した降下電圧を入力され、オペアンプにより構成された差動増幅回路により増幅して出力する電圧増幅部、４７は電圧増幅部４６で増幅された降下電圧をデータ化して制御部３６に入力するＡ／Ｄコンバーターである。抵抗４４と電圧増幅部４６が実施の形態１の検知部である。本実施の形態１においては、リレー３９，４０，４５を切り替えることにより、第１作用電極１０と第１対極１１間を流れる電流を検知する第１検知部と、第２作用電極１０′と第２対極１１′間を流れる電流を検知する第２検知部とを兼用することができ、回路が簡略化されている。同様に、本実施の形態１ではＤ／Ａコンバーター３７，４１の出力電圧は制御部３６からのデータにより可変にできるので、第１作用電極１０と第１対極１１間，第２作用電極１０′と第２対極１１′間の電圧を等電圧だけではなく別の電圧とすることができる。制御部３６は検知したデータを第１作用電極１０と第１対極１１間，第２作用電極１０′と第２対極１１′間を流れる電流値として内部のメモリに記憶する。４８は演算部で、全光線受光量検出部Ａと紫外線カット受光量検出部Ｂのそれぞれで測定した還元電流値の差をとり、メモリされている紫外線の検量線データと比較して、内挿して紫外線の受光量を算出する。
【００６４】
続いて、本実施の形態１の制御回路がどのように動作するのか説明する。測定チップＣを、本体１の測定チップ挿入部６に挿入し、電源ボタン５を押して起動させる。さらに、測定を開始するためにスタートボタン３を押すと、制御部３６は対応する制御回路の各スイッチをＯＮし、紫外線センサーを動作可能にする。次いで、制御部３６は全光線受光量検出部Ａに受光量の検出を開始させるように指令する。紫外線を含んだ全光線（日光）による３−メチル−ｐ−ベンゾキノンの還元電流値を測定するため、制御部３６は第１対極１１、第１作用電極、第１比較電極１２に通電する必要から、リレー４０をＡ′接点側、リレー３９をＡ′′′接点側に接続し、リレー４５をＡ″側に接続する。その後、制御部３６は第１比較電極１２に対するデータをメモリから読み出し、Ｄ／Ａコンバーター３７でアナログ化してオペアンプ３８に入力する。オペアンプ３８はイマジナリショートを利用して第１比較電極をデータどおり基準の電圧になるように第１対極１１に印加する電位を制御する。同時に、制御部３６は第１作用電極１０に対するデータをメモリから読み出し、Ｄ／Ａコンバーターでアナログ化してオペアンプ４３に入力する。オペアンプ４３は電流を検出するための抵抗４４で電圧降下が起こり、出力側の第１作用電極１０の電位に変化がでるのを防止するため、ホロアとなっている。これにより第１作用電極１０はデータどおりに所定の電位に制御される。
【００６５】
実施の形態１では、全光線受光量検出部Ａの光照射量を検出するためボルタンメトリーするから、制御部３６は第１作用電極１０の電位を、１０ｍＶ／ｓ〜２００ｍＶ／ｓの掃引速度、＋８００ｍＶ〜−１０００ｍＶの範囲で掃引する。第１対極１１には、第１作用電極１０を第１比較電極１２の電位を基準にしたとき、掃引する所定の電位になるような電位がオペアンプ３８のイマジナリショートにより印加される。このとき第１作用電極１０を流れる還元電流値は抵抗４４による電圧降下で検出され、電圧増幅部４６で増幅してからＡ／Ｄコンバーター４７を介してデータ化して制御部３６に入力される。制御部３６は電流値のデータの中でボルタモグラムを構成するデータの中で、ピーク値となるデータを選択してメモリする。このデータが全光線受光量検出部Ａの３−メチル−ｐ−ベンゾキノンに対する劣化データである。
【００６６】
続いて、制御部３６は、紫外線カット受光量検出部Ｂに紫外線をカットされた光の受光量を検出するように指令する。紫外線カット受光量検出部Ｂにより受光量を検出する場合も、以上説明した全光線受光量検出部Ａによる検出と同様である。紫外線をカットした光線による３−メチル−ｐ−ベンゾキノンの還元電流を測定するため、制御部３６は第２対極１１′、第２作用電極１０′、第２比較電極１２′に通電する必要から、リレー４０をＢ′接点側、リレー３９をＢ′′′接点側に接続し、リレー４５をＢ″側に接続する。その後、制御部３６は第２比較電極１２′に対するデータをメモリから読み出し、Ｄ／Ａコンバーター３７でアナログ化してオペアンプ３８に入力する。オペアンプ３８はイマジナリショートを利用して第２比較電極をデータどおり基準の電圧になるように第２対極１１′に印加する電位を制御する。また、制御部３６は第２作用電極１０′に対するデータをメモリから読み出し、Ｄ／Ａコンバーターでアナログ化してオペアンプ４３に入力する。オペアンプ４３は電流を検出するための抵抗４４で電圧降下が起こり、出力側の第２作用電極１０′の電位に変化がでるのを防止するため、ホロアとなっている。これにより第２作用電極１０′はデータどおりに所定の電位に制御される。制御部３６は第２作用電極１０′の電位を、１０ｍＶ／ｓ〜２００ｍＶ／ｓの掃引速度、＋８００ｍＶ〜−１０００ｍＶの範囲で掃引する。第２対極１１′には、第２作用電極１０′を第２比較電極１２′の電位を基準にしたとき、掃引電位になるような電位がオペアンプ３８のイマジナリショートにより印加される。このとき第２作用電極１０′を流れる還元電流値は抵抗４４による電圧降下で検出され、電圧増幅部４６で増幅してからＡ／Ｄコンバーター４７を介してデータ化して制御部３６に入力される。制御部３６は電流値のデータの中でボルタモグラムを構成するデータの中で、ピーク値となるデータを選択してメモリする。このデータが紫外線カット受光量検出部Ｂの３−メチル−ｐ−ベンゾキノンに対する劣化データである。
【００６７】
制御部３６が、全光線受光量検出部Ａの３−メチル−ｐ−ベンゾキノンに対する劣化データと、全光線受光量検出部Ａの３−メチル−ｐ−ベンゾキノンに対する劣化データを得ると、演算部４８がメモリされている紫外線の検量線と比較することにより、紫外線の受光量を算出するものである。
【００６８】
ところで、以上説明した実施の形態１は、制御部３６が紫外線量をボルタンメトリーすることによって還元電流のピーク値を求めているが、上述のクロノアンペロメトリーすることでファラデー電流を測定して紫外線の受光量を算出することもできる。この場合、制御部３６はリレー４０をＡ′接点、リレー４５をＡ″接点、リレー３９をＡ′′′接点に設定し、第１作用電極１０にパルス状またはステップ状の電圧を印加する。このとき第１作用電極１０を流れる還元電流値を抵抗４４によって検出し、電圧増幅部４６、Ａ／Ｄコンバーター４７を介してデータ化して制御部３６に入力する。制御部３６は電流値のデータの中でファラデー電流とみられるデータを選択してメモリする。次いで、制御部３６はリレー４０をＢ′接点、リレー４５をＢ″接点、リレー３９をＢ′′′接点に切り替え、第２作用電極１０′パルス状またはステップ状の電圧を印加する。このとき流れる還元電流値を抵抗４４によって検出し、電圧増幅部４６、Ａ／Ｄコンバーター４７を介してデータ化して制御部３６に入力する。制御部３６は電流値のデータの中でファラデー電流とみられるデータを選択してメモリする。演算部４８は、これらのデータから、予めメモリしておいた紫外線照射量の検量線と比較することで紫外線量を算定できるものである。
【００６９】
このように、本実施の形態１の紫外線センサーは、ボルタンメトリーによって全光線の照射量を測定するとともに、紫外線を除いた光の照射量を測定し、２つの照射量の差をとるから、測定チップに照射された紫外線の量を算出できる。また、クロノアンペロメトリーすることによって測定チップに照射された紫外線の量を短時間で測定できる。
【００７０】
【発明の効果】
本発明に係る紫外線測定用チップは、全光線受光量検出部と紫外線カット受光量検出部を備えて、収容されたキノンが紫外線の照射で減少したものと、減少しないものとの２つを測定し、両者の差を計算して紫外線照射量を算出するから、小量の試薬で測定でき、コンパクトかつ簡単に操作でき、持ち運びが容易で、受光時間の長さによらず、精度の高い紫外線量を測定することができる。
【００７１】
さらに本発明に係る紫外線測定用チップは、全光線透過板が石英ガラスを含んでいるから、他の周波数の光を遮断することなく、紫外線を９９％以上透過させ、安価である。
【００７２】
さらに本発明に係る紫外線測定用チップは、紫外線カット透過板が紫外線カットフィルターを備えているから、他の周波数の光を遮断することなく、紫外線のみをカットできる。
【００７３】
さらに本発明に係る紫外線測定用チップは、第１作用電極と第２作用電極がそれぞれ炭素，ガラス状炭素，金の中から選ばれた１以上の材料から構成されているから、電流値を安定して測定できる。
【００７４】
さらに本発明に係る紫外線測定用チップは、第１対極と第２対極が耐食性導電体から構成されているので、劣化もなく、安定して測定できる。
【００７５】
さらに本発明に係る紫外線測定用チップは、耐食性導電体が白金，ステンレス，白金含有合金，炭素の中から選ばれた１以上の材料から構成されているから、劣化がほとんどなく、安定した測定ができる。
【００７６】
さらに本発明に係る紫外線測定用チップは、第１比較電極と第２比較電極がそれぞれ金または炭素から構成されているから、比較電極が単純で安価になる。
【００７７】
また本発明に係る紫外線センサーは、紫外線測定用チップを挿入する測定用チップ挿入部を備え、紫外線測定用チップを挿入したとき第１作用電極と第１比較電極間の電位を掃引するとともに第２作用電極と第２比較電極間の電位を掃引する制御部と、第１作用電極と第１対極間に流れる電流を検知する第１検出部と、第２作用電極と第２対極間に流れる電流を検知する第２検出部とを有し、第１検出部と第２検出部で検知された電流値の差から紫外線量を算出する演算部を備えたから、小量の試薬で測定でき、コンパクトかつ簡単に操作でき、持ち運びが容易で、受光時間の長さによらず、精度の高い紫外線量を測定することができる。
【００７８】
また本発明に係る紫外線センサーは、紫外線測定用チップを挿入する測定用チップ挿入部を備え、紫外線測定用チップを挿入したとき第１作用電極と第１比較電極間を第１比較電極を基準にして所定の電位に制御するとともに第２作用電極と第２比較電極間を第２比較電極を基準にして所定の電位に制御する制御部と、第１作用電極と第１対極間に流れる電流を検知する第１検出部と、第２作用電極と第２対極間に流れる電流を検知する第２検出部とを有し、第１検出部と第２検出部で検知された電流の差から紫外線量を算出する演算部を備えたから、小量の試薬で測定でき、コンパクトかつ簡単に操作でき、制御部がより簡単であり、持ち運びが容易で、受光時間の長さによらず、精度の高い紫外線量を測定することができる。
【００７９】
さらに本発明に係る紫外線センサーは、第２電源と第１電源を共用するから、電源回路がコンパクトになる。
【００８０】
さらに本発明に係る紫外線センサーは、制御部が１０ｍＶ／ｓ〜２００ｍＶ／ｓの掃引速度で掃引するから、電流のプレピーク値を精度良く測定できる。
【００８１】
また本発明に係る紫外線測定方法は、キノン，有機溶媒，電解質含有の共存電解液に全光線を照射するとともに、キノン，有機溶媒，電解質含有の共存電解液に紫外線をカットした光を照射し、全光線を照射した共存電解液と紫外線をカットした光を照射した共存電解液をそれぞれボルタンメトリーし、還元電流の差をとることにより紫外線量を算出するから、小量の試薬で、簡単に測定でき、精度が高い紫外線量を測定できる。
【００８２】
また本発明に係る紫外線測定方法は、キノン，有機溶媒，電解質含有の共存電解液に全光線を照射するとともに、キノン，有機溶媒，電解質含有の共存電解液に紫外線をカットした光を照射し、全光線を照射した共存電解液と紫外線をカットした光を照射した共存電解液をそれぞれクロノアンペロメトリーし、還元電流の差をとることにより紫外線量を算出するから、小量の試薬で、さらに簡単且つ迅速に測定でき、精度が高い紫外線量を測定できる。
【図面の簡単な説明】
【図１】本発明の実施の形態１における紫外線センサーの概略外観図
【図２】本発明の実施の形態１における紫外線センサーの紫外線測定用チップの説明図
【図３】キノン含有の共存電解液への光の照射時間とキノン還元電流のピーク値の関係を示すグラフ
【図４】ボルタンメトリーを行ったときに現れる還元電流の説明図
【図５】クロノアンペロメトリーを行ったときに現れるファラデー電流の説明図
【図６】本実施の形態１における紫外線センサーの制御回路図
【符号の説明】
１本体
２表示部
３スタートボタン
３′ スタート・スイッチ
４モード切り替えボタン
４′ モード切り替えスイッチ
５電源ボタン
６測定チップ挿入部
７第１作用電極用パターン
７第２作用電極用パターン
７ｔ1 第1作用電極用の端子
７ｔ2 第２作用電極用の端子
８第1対極用パターン
８′ 第２対極用パターン
８ｔ1 第1対極用の端子
８ｔ2 第２対極用の端子
９第1比較電極用パターン
９′ 第２比較電極用パターン
９ｔ1 第1比較電極用の端子
９ｔ2 第２比較電極用の端子
１０第1作用電極
１０′ 第２作用電極
１１第1対極
１１′ 第２対極
１２第1比較電極
１２′ 第２比較電極
１３第1光透過窓
１３′ 第２光透過窓
１４第1反応室
１４′ 第２反応室
１５基板
１６全光線透過板
１６′ 紫外線カット透過板
３５ＬＣＤ
３６制御部
３７，４１Ｄ／Ａコンバーター
３８，４３オペアンプ
３９，４０，４５リレー
４４抵抗
４６電圧増幅部
４７Ａ／Ｄコンバーター
４８演算部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an ultraviolet ray measuring chip provided with a first reaction chamber that receives all light rays and a second reaction chamber that receives ultraviolet light that has been cut in order to measure the amount of ultraviolet rays, and the ultraviolet ray measuring chip. The present invention relates to an ultraviolet sensor that is attached and electrochemically calculates the amount of ultraviolet rays, and further relates to an ultraviolet ray measuring method that electrochemically calculates the amount of ultraviolet rays.
[0002]
[Prior art]
The light in the range of 400 to 770 nm is called a so-called visible ray, and is a ray that can be seen by human eyes. Of these, the light with a short wavelength of around 400 nm is a violet light, and the light with a shorter wavelength close to the violet is called an ultraviolet ray. There are also three types of ultraviolet rays. The first is a UV-A wave, which has a wavelength of 320 to 400 nm, and has a property of passing through the epidermis and directly hitting the dermis. It causes wrinkles and sagging. The second one has a wavelength of 290 to 320 nm and is called a UV-B wave, which is blocked by the epidermis and causes skin cancer, blotches and freckles, and has the strongest influence on human skin. The third one has a wavelength of 290 nm or less and is called a UV-C wave, and is almost absorbed by the ozone layer, but affects the gene and causes skin cancer. The light having the longest wavelength among visible light rays is red light existing in the vicinity of 760 nm. When the wavelength exceeds 760 nm, the light exceeds red and is called infrared light. Among these, short infrared rays having a wavelength near 760 nm are called near infrared rays, and infrared rays having a long wavelength of 50 to 1000 μm are called far infrared rays. This is an energy wave that is most easily absorbed by humans.
[0003]
Among the lights described above, the most harmful light is ultraviolet rays. Ultraviolet rays have an effect on the skin as described above, and there are not only serious effects that cause lesions on skin tissue, but also minor effects that occur daily. That is, when melanocytes (pigment-forming cells) in the skin are exposed to ultraviolet rays, melanin pigments are produced, and the skin becomes black and spots and freckles are produced. On the other hand, the first of the serious effects that cause lesions is that UV rays damage the genes in the nucleus of skin cells and cause cancer. Normally, even if some genes are damaged, the enzyme that cures them works and is repaired, but if a strong sunburn or wound is formed by a large amount of exposure, the enzyme is not fully repaired and the cell is mutated Cause the risk of developing cancer.
[0004]
By the way, in recent years, chlorofluorocarbon gas, which has been used extensively as a stable and excellent refrigerant, has been released into the atmosphere without careful examination, and the ozone layer surrounding the earth's atmosphere is destroyed. It has occurred. The ozone layer plays an important role in protecting the organisms by blocking the ultraviolet rays that fall on the earth, but because the ozone layer is destroyed, the amount of ultraviolet rays that reach the earth's surface increases, skin cancer occurs frequently, and organisms are greatly affected. It has become like this. The incidence of skin cancer in Japan was about 1 in 100,000 in the 1960s and 1970s, but is now increasing to about 5 per 100,000. However, this ratio is much smaller than the ratio of 800 per 100,000 in Australia and 250 per 100,000 in the United States, but it can be said that it has definitely increased. And when ozone decreases by 1%, there is a report that ultraviolet rays increase by 2% and skin cancer patients increase by about 3-5% (Masahiko Ichihashi, “Medical Renaissance”, Yomiuri Shimbun, [online], (March 2000) Search on month 3), <URL: http://www3.yomiuri.co.jp/medicasl/life/96112901.htm>).
[0005]
By the way, the proportion of skin cancer patients among the dermatological outpatients in the 1970s and 1980s was investigated in 24 university hospitals nationwide. Comparing the two ages, skin cancer patients in the 1980s increased by 17% in basal cell carcinomas in the lowermost layer of the epidermis, and the skin was precancerous and had red and black spots and sores on the skin. It has been reported that possible actinic keratosis has increased by 84%. Therefore, it is an important factor for growth that children etc. play outdoors outdoors during the day, but when playing for a long time in sports or recreation, etc. It turns out that measures against ultraviolet rays such as applying sunscreen cream are necessary. In particular, patients with xeroderma pigmentosum that cause extreme sunburn even with very small amounts of UV rays develop cancers that are 1000 to 2000 times more common than normal people because of the genetic defect in the enzyme system that repairs genes that have been damaged by UV rays. There is a risk, and UV protection must be taken with great care.
[0006]
Prof. Masamitsu Ichihashi of Kobe University is conducting an experiment to show how important this UV countermeasure is. The experiment was to thoroughly teach UV protection measures such as applying sunscreen cream and wearing a hat to 4 year old and 2 year old sisters suffering from xeroderma pigmentosum. It is a follow-up study of how much the difference between two years of two people who have been defenseless until then can affect the carcinogenesis by blocking the effects. As a result, both of them developed cancer, but the older sister developed cancer at the age of 13, and the younger sister developed cancer at the age of 23. In other words, because my sister had been exposed to many UV rays for two years in her childhood, she had developed cancer as early as 10 years. It is a fact that shows how important protection from UV rays is. Moreover, ultraviolet rays also have an adverse effect on the immune system of the skin. Animal experiments have demonstrated that UV irradiation reduces systemic immunity and makes it more susceptible to infections.
[0007]
If immunity decreases, cancer cells cannot be eliminated even if they are generated. In a study in the United States, 40% of normal people and 95% of skin cancer patients are immunized when exposed to about 4 times the amount of UV rays, based on the amount of UV light that makes the skin lightly red. It has been reported that the force did not work properly.
[0008]
By the way, in Europe and the United States, there is a general awareness that sunburn is dangerous, but most skin cancer patients in Japan are elderly, and it often takes more time than young people to get sick. In Japan, it is said that the recognition of ultraviolet rays is sweet. However, in the present age when the ozone layer is beginning to be destroyed, it cannot be said that it is irrelevant to ourselves and is being held by the chief.
[0009]
This ozone layer is formed by stratospheric oxygen (O ₂ ) Ozone (O _Three ) Is a layer of the atmosphere that has been changed to a higher concentration. By such a reaction, harmful ultraviolet rays such as UV-C contained in the sunlight are cut off, and the life of living creatures on the surface is protected. However, as already mentioned, Freon gas has been used extensively as a cleaning liquid for refrigerants and semiconductors for the last couple of decades, and it has been released into the atmosphere without fully considering its environmental impact. It is said that chlorine in Freon gas is released by receiving ultraviolet rays in the stratosphere, and this reacts with ozone in the ozone layer and further decomposes into oxygen and CLO. When ozone concentration decreases in this way, the ozone layer no longer has the ability to block harmful ultraviolet rays, the ultraviolet rays reach the surface of the earth on a daily basis, and living organisms are exposed to a large amount of ultraviolet rays without their knowledge. This has had a major impact on life support.
[0010]
Therefore, the necessity of actually measuring the amount of received light has not increased as much as the amount of ultraviolet rays in daily life. In response to this situation, the Environment Agency and the Japan Meteorological Agency have started monitoring ultraviolet rays in Tokyo since 1993. However, there have been few measuring apparatuses for measuring ultraviolet rays.
[0011]
Then, what kind of apparatus has existed in the conventional ultraviolet ray measuring apparatus is demonstrated. A typical example is the Brewer spectrophotometer. This Brewer spectrophotometer has the characteristic that UV-B ultraviolet rays can be spectroscopically observed with high accuracy at wavelengths of 0.5 nm. However, the Brewer spectrophotometer is somewhat unstable and requires strict maintenance. As another ultraviolet ray measuring apparatus, there is a UV sensor whose color gradually changes from white to blue when exposed to sunlight. The amount of ultraviolet rays is judged by looking at the color change. In addition, there is an ultraviolet intensity sensor that electrically measures ultraviolet rays (Japanese Patent Laid-Open No. 9-304177). This UV intensity sensor has a quartz fiber whose one end is installed in the light irradiator, a UV bandpass filter that extracts only the UV component from the light guided by this quartz fiber, and a light that measures the intensity of this UV component. The apparatus includes a side light part provided with an intensity sensor, and an intensity meter body provided with a display unit for displaying the ultraviolet intensity based on an ultraviolet intensity signal from the side light part.
[0012]
[Problems to be solved by the invention]
However, although the conventional Brewer spectrophotometer is highly accurate, it is slightly less stable, so strict maintenance management is required, and inspection and calibration must be performed very frequently. In addition, it is expensive and cannot be carried around. Unless it is an expert, it cannot be used, and cannot be said to be a measurement device suitable for measuring the amount of irradiation that ordinary people take every day.
[0013]
Next, the UV sensor has a problem that accuracy is poor because it is judged by looking at a simple color change, and there is a problem that there is a large individual difference in evaluation of measurement results because it depends on a personal feeling.
[0014]
Furthermore, the conventional ultraviolet intensity sensor can measure only the intensity at that time, and cannot measure the accumulated amount of ultraviolet rays that have been taken throughout the day. At the same time, this sensor was complex in structure and difficult to carry.
[0015]
Therefore, in order to solve such problems, the present invention is an ultraviolet ray measuring chip that can measure with a small amount of reagent, is compact and easy to handle, and can accurately measure the amount of ultraviolet rays regardless of the length of light receiving time. The purpose is to provide.
[0016]
In addition, the present invention provides an ultraviolet sensor that can measure with a small amount of reagent, is compact and easy to operate, is easy to carry, and measures the amount of ultraviolet rays with high accuracy regardless of the length of light reception time. Objective.
[0017]
An object of the present invention is to provide an ultraviolet ray measuring method that can be easily measured with a small amount of reagent and that can measure an ultraviolet ray amount with high accuracy regardless of the length of the light receiving time.
[0018]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the ultraviolet ray measuring chip of the present invention is an ultraviolet ray measuring chip including a total light reception amount detection unit and an ultraviolet cut light reception amount detection unit, and the total light reception amount detection unit includes: A first reaction chamber that contains a quinone, an organic solvent, and an electrolyte-containing coexisting electrolyte solution and is provided with a first light transmission window, a total light transmission plate provided in the first light transmission window, and the first reaction A first working electrode, a first counter electrode, and a first comparison electrode that are disposed indoors and are immersed in the coexisting electrolyte solution are provided, and the ultraviolet ray cut received light amount detection unit includes quinone, an organic solvent, and an electrolyte. A coexisting electrolyte solution, a second reaction chamber provided with a second light transmission window, an ultraviolet-cut transmission plate provided in the second light transmission window, disposed in the second reaction chamber, and Second working electrode, second counter electrode and second reference electrode immersed in coexisting electrolyte A plurality of terminals electrically connected to the first working electrode, the first counter electrode, the first comparison electrode, the second working electrode, the second counter electrode, and the second comparison electrode, respectively. It is characterized by having.
[0019]
Thereby, it can measure with a small amount of reagent, is compact and easy to handle, and can measure the amount of ultraviolet rays with high accuracy regardless of the length of light reception time.
[0020]
The ultraviolet sensor of the present invention is the above A measuring chip insertion portion provided with a connector terminal that can be electrically connected to each of the terminals, and when the ultraviolet measuring chip is inserted, the first working electrode and the first working electrode A first power source capable of applying a voltage between one counter electrode and a second power source capable of applying a voltage between the second working electrode and the second counter electrode; and between the first working electrode and the first comparison electrode A controller that sweeps a potential and sweeps a potential between the second working electrode and the second comparison electrode; a first detector that detects a current flowing between the first working electrode and the first counter electrode; A second detection unit configured to detect a current flowing between the second working electrode and the second counter electrode, and calculating an ultraviolet ray amount from a difference between current values detected by the first detection unit and the second detection unit; It is characterized by having an arithmetic unit for performing the above.
[0021]
Thereby, it can measure with a small amount of reagent, can be operated in a compact and simple manner, is easy to carry, and can measure the amount of ultraviolet rays with high accuracy regardless of the length of the light receiving time.
[0022]
Furthermore, the ultraviolet ray measurement method of the present invention irradiates the quinone, organic solvent, electrolyte-containing coexisting electrolyte solution with all light, and irradiates the quinone, organic solvent, electrolyte-containing coexisting electrolyte solution with ultraviolet light cut, It is characterized in that the amount of ultraviolet rays is calculated by voltammetrically measuring the coexisting electrolyte irradiated with all light rays and the coexisting electrolyte irradiated with light cut from ultraviolet rays, and taking the difference in reduction current value.
[0023]
Thereby, it is possible to easily measure with a small amount of reagent, and it is possible to measure the amount of ultraviolet rays with high accuracy regardless of the length of the light receiving time.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
The present invention For UV measurement Is a UV measuring chip having a total light reception amount detection unit and a UV cut light reception amount detection unit, and the total light reception amount detection unit contains a coexisting electrolyte containing quinone, an organic solvent, and an electrolyte. A first reaction chamber provided with a first light transmission window; a total light transmission plate provided in the first light transmission window; and a first reaction chamber disposed in the first reaction chamber and immersed in the coexisting electrolyte. A first working electrode, a first counter electrode, and a first comparison electrode are provided, and the ultraviolet ray cut received light amount detection unit contains a quinone, an organic solvent, an electrolyte-containing coexisting electrolyte, and a second light transmission window A second reaction chamber provided; an ultraviolet-cut transmission plate provided in the second light transmission window; a second working electrode disposed in the second reaction chamber and immersed in the coexisting electrolyte; Two counter electrodes and a second reference electrode are provided, the first working electrode and the first counter electrode Since the ultraviolet ray measuring chip includes a plurality of terminals electrically connected to the first comparison electrode, the second working electrode, the second counter electrode, and the second comparison electrode, It can be measured with a small amount of reagent, is compact and easy to operate, is easy to carry, and can measure the amount of ultraviolet rays with high accuracy regardless of the length of light reception time.
[0025]
Furthermore, the ultraviolet ray measuring chip according to the present invention That the total light transmission plate contains quartz glass. Features UV measurement chip Therefore, 99% or more of ultraviolet rays are transmitted without blocking light of other frequencies, and it is inexpensive.
[0026]
Furthermore, the ultraviolet ray measuring chip according to the present invention The ultraviolet cut transmission plate is equipped with an ultraviolet cut filter. Features UV measurement chip Therefore, only ultraviolet rays can be cut without blocking light of other frequencies.
[0027]
Furthermore, the ultraviolet ray measuring chip according to the present invention Is characterized in that each of the first working electrode and the second working electrode is made of one or more materials selected from carbon, glassy carbon, and gold. UV measurement chip Therefore, the current value can be measured stably.
[0028]
Further, the ultraviolet ray measuring chip according to the present invention is The first counter electrode and the second counter electrode are each composed of a corrosion-resistant conductor. Features UV measurement chip Therefore, it can be measured stably without deterioration.
[0029]
Furthermore, the ultraviolet ray measuring chip according to the present invention The corrosion-resistant conductor is composed of one or more materials selected from platinum, stainless steel, platinum-containing alloys, and carbon. Features UV measurement chip Therefore, there is almost no deterioration and stable measurement can be performed.
[0030]
Furthermore, the ultraviolet ray measuring chip according to the present invention Is an ultraviolet ray measuring chip in which each of the first reference electrode and the second comparison electrode is made of gold or carbon, so that the comparison electrode is simple and inexpensive.
[0031]
Also, the ultraviolet sensor according to the present invention Comprises a measuring chip insertion portion provided with a connector terminal capable of being electrically connected to each of the terminals, into which the first working electrode is inserted when the ultraviolet measuring chip is inserted. And a first power source capable of applying a voltage between the first counter electrode, and a second power source capable of applying a voltage between the second working electrode and the second counter electrode, the first working electrode and the first comparison A controller that sweeps the potential between the electrodes and sweeps the potential between the second working electrode and the second comparison electrode, and a first detection that detects a current flowing between the first working electrode and the first counter electrode And a second detection unit that detects a current flowing between the second working electrode and the second counter electrode, and an ultraviolet ray is detected from a difference between current values detected by the first detection unit and the second detection unit. Ultraviolet characterized by having a calculation unit to calculate quantity Since a sensor, it can be measured with a little reagent, compact and simple to operate, easy to carry, regardless of the length of the light receiving time can be measured with high accuracy the amount of ultraviolet rays.
[0032]
The ultraviolet sensor according to the present invention is the above-mentioned A measuring chip insertion portion provided with a connector terminal that can be electrically connected to each of the terminals, and when the ultraviolet measuring chip is inserted, the first working electrode and the first working electrode A first power source capable of applying a voltage between one counter electrode, and a second power source capable of applying a voltage between the second working electrode and the second counter electrode, and between the first working electrode and the first comparison electrode. A control unit that controls the potential between the second working electrode and the second comparison electrode to a predetermined potential with reference to the second comparison electrode; A first detector for detecting a current flowing between the first working electrode and the first counter electrode; and a second detector for detecting a current flowing between the second working electrode and the second counter electrode; Current value detected by one detector and the second detector The UV sensor is equipped with a calculation unit that calculates the UV amount from the difference, so it can be measured with a small amount of reagent, can be operated in a compact and simple manner, the control unit is simpler, and it is easy to carry. The amount of ultraviolet rays can be measured with high accuracy regardless of the length of the light receiving time.
[0033]
Furthermore, the ultraviolet sensor according to the present invention Indicates that the second power source is the first power source. Features UV sensor Therefore, the power circuit becomes compact.
[0034]
Furthermore, the ultraviolet sensor according to the present invention Means that the controller sweeps at a sweep speed of 10 mV / s to 200 mV / s. Features UV sensor Therefore, the current pre-peak value can be measured with high accuracy.
[0035]
The ultraviolet ray measuring method according to the present invention is In addition to irradiating the coexisting electrolyte containing quinone, organic solvent and electrolyte with total light, irradiating the coexisting electrolyte containing quinone, organic solvent and electrolyte with ultraviolet light, It is an ultraviolet ray measurement method characterized by calculating the amount of ultraviolet rays by voltammetrically measuring the coexisting electrolytes irradiated with light cut from ultraviolet rays and taking the difference in reduction current value. It can measure the amount of ultraviolet rays with high accuracy.
[0036]
The ultraviolet ray measuring method according to the present invention Irradiates the coexisting electrolyte containing quinone, organic solvent, and electrolyte with total light, and irradiates the coexisting electrolyte containing quinone, organic solvent, and electrolyte with ultraviolet light, and then irradiates with all light. A small amount of reagent because the amount of ultraviolet light is calculated by chronoamperometry of each coexisting electrolyte that has been irradiated with light that is cut from ultraviolet light and taking the difference in the reduction current value. Thus, the amount of ultraviolet rays can be measured more easily and quickly, and with high accuracy.
[0037]
Hereinafter, embodiments of the present invention will be described with reference to FIGS.
[0038]
(Embodiment 1)
First, an ultraviolet sensor and an ultraviolet measurement chip according to an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic external view of an ultraviolet sensor according to Embodiment 1 of the present invention. In FIG. 1, 1 is a main body, 2 is a display unit for converting a measured value into an ultraviolet ray amount, and 3 is a start / stop button for starting measurement, 4 is a mode switch for calling stored data and switching various modes. Button 5 is a power button for turning on / off the power, and 6 is an ultraviolet ray measuring chip (hereinafter referred to as a measuring chip) C, which will be described later. It is a measurement chip insertion part to measure. Inside the measurement chip insertion portion 6, connector terminals (not shown) that can be connected to the terminals of the measurement chip C are provided.
[0039]
FIG. 2 is an explanatory diagram of the ultraviolet ray measuring chip of the ultraviolet sensor according to Embodiment 1 of the present invention. 7 is a pattern for a first working electrode, 7 'is a pattern for a second working electrode, 8 is a pattern for a first counter electrode, 8' is a pattern for a second counter electrode, 9 is a pattern for a first comparison electrode, and 9 'is a second pattern Reference electrode pattern 10 is a first working electrode, 10 'is a second working electrode, 11 is a first counter electrode, 11' is a second counter electrode, 12 is a first comparison electrode, and 12 'is a second comparison electrode. 7t1 is a terminal for the first working electrode, 7t2 is a terminal for the second working electrode, 8t1 is a terminal for the first counter electrode, 8t2 is a terminal for the second counter electrode, 9t1 is a terminal for the first comparison electrode, and 9t2 is a terminal for the first comparison electrode This is a terminal for the second comparison electrode. Reference numeral 15 denotes a substrate.
[0040]
The first working electrode pattern 7 is a thin film formed by printing a conductive carbon paste containing a resin binder on the substrate 15 in a thin band shape by screen printing. The first working electrode pattern 7 is connected to the first working electrode 10. The first working electrode 10 is constituted by a carbon electrode called glassy carbon, a carbon material obtained by sintering a plastic foam called PFC at 1000 ° C. to 2000 ° C., or a thin film formed by vapor deposition or sputtering of gold. It is appropriate to configure the second working electrode 10 'in exactly the same manner. However, the first working electrode 10 and the first working electrode pattern 7 are not formed of different materials in this way, but are screen-printed with the conductive carbon paste together with the first working electrode pattern 7 and integrally formed as a thin film. It is desirable to reduce the number of processes and reduce costs. As with the first working electrode 10, it is appropriate to integrally mold the second working electrode 10 '.
[0041]
Next, the first counter electrode pattern 8 is formed by thinly forming a conductive carbon paste containing a resin binder on the substrate 15 by screen printing in a thin band shape. The first counter electrode pattern 8 is connected to the first counter electrode 11. The first counter electrode 11 is made of a conductive material such as platinum, graphite, gold, stainless steel, aluminum or the like. It is appropriate to configure the second counter electrode 11 'in exactly the same manner. Similarly to the relationship between the first working electrode 10 and the first working electrode pattern 7, the first counter electrode 11 is not made of a material different from that of the first counter electrode pattern 8, but is energized together with the first counter electrode pattern 8. It is appropriate to integrally form the conductive carbon paste because the number of processes is reduced and the cost is also reduced. As with the first counter electrode 11, it is appropriate to integrally mold the second counter electrode 11 '.
[0042]
Further, the first comparative electrode pattern 9 is obtained by thinning the conductive carbon paste containing a resin binder onto the substrate 15 by printing it thinly on the substrate 15 by screen printing. The first comparison electrode pattern 9 is connected to the first comparison electrode 12. The first comparison electrode 12 is composed of a carbon electrode called glassy carbon, a carbon material obtained by sintering a plastic foam called PFC at 1000 ° C. to 2000 ° C., or a thin film formed by vapor deposition or sputtering. The same applies to the second reference electrode pattern 9 'and the second reference electrode 12'.
[0043]
The first working electrode terminal 7t1, the first counter electrode terminal 8t1, the first reference electrode terminal 9t1, the second working electrode terminal 7t2, the second counter electrode terminal 8t2, and the second reference electrode terminal It is desirable that the terminal 9t2 is made of a conductive material such as platinum, gold, stainless steel or the like so that the contact strength of the connector is increased and a connection with low electrical resistance is possible.
[0044]
2, 13 is a first light transmission window, 13 'is a second light transmission window, 14 is a first reaction chamber, 14' is a second reaction chamber, 16 is a total light transmission plate, and 16 'is an ultraviolet ray. It is a cut transmission plate. A first light transmission window 13 that transmits all light rays is opened on the surface of the first reaction chamber 14, and a total light transmission plate 16 is attached to the first light transmission window 13. Similarly, the surface of the second reaction chamber 14 ′ is opened with a second light transmission window 13 ′ through which light cut only by ultraviolet rays is transmitted, and an ultraviolet cut transmission plate 16 ′ is attached to the second light transmission window 13. Yes.
[0045]
In the first reaction chamber 14, the first working electrode 10, the first counter electrode 11, and the first comparison electrode 12 are arranged in a non-contact state with each other, and each of them is a first working electrode pattern 7 and a first counter electrode use. The pattern 8 and the first reference electrode pattern 9 lead to the outside. The derived end portions of the first working electrode pattern 7, the first counter electrode pattern 8, and the first comparison electrode pattern 9 are the first working electrode terminal 7t1, the first counter electrode terminal 8t1, the first The reference electrode terminal 9t1 is electrically connected when it is attached to the measuring chip insertion portion 6. The electrode portions of the first working electrode 10, the first counter electrode 11, and the first comparison electrode 12, the first working electrode terminal 7t1, the first counter electrode terminal 8t1, and the first comparison electrode terminal 9t1 Except for the portions, the surfaces of the first working electrode pattern 7, the first counter electrode pattern 8, and the first comparison electrode pattern 9 are covered with an insulating material.
[0046]
Similarly, in the second reaction chamber 14 ', the second working electrode 10', the second counter electrode 11 ', and the second comparison electrode 12' are arranged in a non-contact state with each other, and each of them is a second working electrode pattern. 7 ', a second counter electrode pattern 8', and a second reference electrode pattern 9 '. The end portions of the derived second working electrode pattern 7 ', second counter electrode pattern 8', and second comparison electrode pattern 9 'are the second working electrode terminal 7t2 and the second counter electrode terminal 8t2. The terminal 9t2 for the second comparison electrode is electrically connected when it is attached to the measuring chip insertion portion 6. The electrode portions of the second working electrode 10 ', the second counter electrode 11', and the second comparison electrode 12 ', the second working electrode terminal 7t2, the second counter electrode terminal 8t2, and the second comparison electrode terminal 9t2 The surfaces of the second working electrode pattern 7 ', the second counter electrode pattern 8', and the second reference electrode pattern 9 'are covered with an insulating material except for the terminal portions.
[0047]
In the first embodiment, the first working electrode pattern 7, the first counter electrode pattern 8, the first comparison electrode pattern 9, the second working electrode pattern 7 ', the second counter electrode pattern 8', All of the second reference electrode patterns 9 'are drawn out in parallel. The first working electrode terminal 7t1, the first counter electrode terminal 8t1, the first reference electrode terminal 9t1, and the second terminal electrode 2t1 are the end parts. The working electrode terminal 7t2, the second counter electrode terminal 8t2, and the second comparison electrode terminal 9t2 are also provided in parallel at substantially equal pitches. As a result, it is possible to reduce the size and electrically connect to the connector terminal in the measurement chip insertion portion 6.
[0048]
By the way, the coexisting electrolyte A and coexisting electrolyte A ′ for electrochemically measuring the amount of received light are accommodated in the first reaction chamber 14 and the second reaction chamber 14 ′ of the first embodiment, respectively. Has been. The coexisting electrolyte A and the coexisting electrolyte A ′ are the same components, both of which are quinones dissolved in an organic solvent such as ethanol or isopropyl alcohol, and further added with an electrolyte such as sodium chloride or lithium chloride. Examples of the quinone used include p-benzoquinone, 3-methyl-p-benzoquinone, o-benzoquinone, diphenoquinone, naphthoquinone, anthraquinone, benzeneazohydroquinone, and derivatives of these quinones. Includes quinones. In Embodiment 1, as the composition of the coexisting electrolytes A and A ′, specifically, 20 mM 3-methyl-p-benzoquinone and 150 mM sodium chloride are dissolved in a solvent having a mixing ratio of ethanol and water of 8 to 2. We use what we made.
[0049]
A total light transmission plate 16 is attached to the first reaction chamber 14 in which the coexisting electrolyte A is accommodated. The total light transmitting plate 16 is suitably made of quartz glass, diamond, sodium chloride single crystal, titania or the like having an ultraviolet transmittance of 99%. In addition, an ultraviolet cut transmission plate 16 'is attached to the second reaction chamber 14' in which the coexisting electrolyte A 'is accommodated. This UV-cut transmission plate 16 'is a transparent resin such as transparent vinyl chloride resin, acrylic resin, polycarbonate resin, methacrylic resin or the like that blocks 90% or more of ultraviolet rays and transmits other rays such as infrared rays, or the surface of ordinary glass In addition, UV cut filters with special treatments such as soft vinyl film, polyurethane film and polyester film are applied.
[0050]
As described above, the first reaction chamber 14 is provided with the first light transmission window 13 and the total light transmission plate 16 is fitted therein, and the coexisting electrolyte A is accommodated therein. In the coexisting electrolyte A, the first working electrode 10, the first counter electrode 11, and the first comparison electrode 12 are immersed in a non-contact state. These constitute the total light reception amount detection unit A of the measurement chip C of the first embodiment. The second reaction chamber 14 'is provided with a second light transmission window 13', and an ultraviolet cut transmission plate 16 'is fitted therein, and the coexisting electrolyte A' is accommodated therein. In the coexisting electrolyte A ′, the second working electrode 10 ′, the second counter electrode 11 ′, and the second comparison electrode 12 ′ are immersed in a non-contact state. These constitute the ultraviolet cut received light amount detection unit B of the measurement chip C of the first embodiment.
[0051]
The measurement chip C has the same effect on the quinone except for the influence of ultraviolet rays, so that the total light reception amount detection unit A and the ultraviolet ray cut reception amount detection unit B are brought close to each other and arranged in the vicinity of two poles. is there. Since the coexisting electrolytes A and A ′ share the degree of deterioration of quinones except for ultraviolet rays, the electrode materials, electrode pattern materials, and the like that constitute the total light reception amount detection unit A and the ultraviolet ray cut reception amount detection unit B are used. It is appropriate to use coexisting electrolytes that are the same and have the same components and the same environment.
[0052]
Next, the reason why the amount of ultraviolet rays can be detected by the measurement chip C of the first embodiment will be described below. FIG. 3 is a graph showing the relationship between the irradiation time of light to the quinone-containing coexisting electrolyte and the peak value of the quinone reduction current. The quinone is 3-methyl-p-benzoquinone, and the irradiated light is 30 W / m. ² Sunlight that hits all ultraviolet rays and all rays. The measurement conditions at this time are that the working electrode and the reference electrode are made of glassy carbon, the counter electrode is made of platinum, and the working electrode has an area of 3.2 mm. ² The coexisting electrolyte is a mixture of 3-methyl-p-benzoquinone 20 mM, sodium chloride 150 mM, and a mixing ratio of ethanol and water 8: 2, and works so that the working electrode becomes the sweep potential based on the reference electrode potential. A voltage was applied between the electrode and the counter electrode, and sweeping was performed at a sweep rate of 100 mV / sec to obtain a reduction current having a peak at the reduction potential of 3-methyl-p-benzoquinone. As will be described later, the reduction current value may be obtained by measuring a Faraday current by applying a predetermined voltage instead of sweeping. As shown in FIG. 3, the peak value of the quinone reduction current decreases as the light reception time increases, regardless of whether ultraviolet rays are received or all sunlight is received. Therefore, the measurement chip is irradiated with ultraviolet rays whose intensity is known in advance, and thereby the coexisting electrolyte in which 3-methyl-p-benzoquinone is reduced is measured electrochemically, and the light receiving time and the intensity of the ultraviolet rays are made variable. If a calibration curve is prepared, the amount of ultraviolet light received by the measuring chip can be measured only by measuring the amount of 3-methyl-p-benzoquinone.
[0053]
However, it is not only light that affects quinone degradation. Factors other than light, such as ambient temperature, also have a significant effect on quinone degradation. Therefore, in the present invention, as described above, two coexisting electrolytes that block only the ultraviolet rays and two coexisting electrolytes that do not block the ultraviolet rays and are given the same conditions are measured almost simultaneously. Yes. Except for ultraviolet rays, both conditions are exactly the same. Therefore, if the amount of quinone is measured with two coexisting electrolytes, the amount of quinone that is excessively reduced in the coexisting electrolyte on the side exposed to ultraviolet rays is proportional to the amount of received light. Will be. In this way, by taking the difference between the coexisting electrolyte measured by blocking ultraviolet light and the coexisting electrolyte measured by transmitting all light, the amount of decrease in quinone due to the influence of ultraviolet light is obtained and measured in advance. The amount of received light of ultraviolet rays can be detected by comparing with the calibration curve of ultraviolet rays. As can be seen from the above description, according to the ultraviolet ray measuring method of the present invention, since the amount of received ultraviolet rays can be accurately measured in proportion to time, the ultraviolet ray for one day that a conventional Brewer spectrophotometer could not perform. The feature is that it can accurately measure the amount of light received for a long time, such as the amount of light received.
[0054]
By the way, how much ultraviolet rays are blocked by the ultraviolet cut transmission plate 16 'depends on the material of the ultraviolet cut transmission plate 16'. Therefore, in the case of a material with a low blocking rate, the difference between the reduction current values when the ultraviolet ray is blocked by the ultraviolet ray cut transmission plate 16 'and when the ultraviolet ray is transmitted by the total light transmission plate 16 is taken, and the blocking rate, that is, the ultraviolet ray. According to the material of the cut transmission plate 16 ', it is appropriate to convert it when 100% is cut off.
[0055]
In the first embodiment, the coexisting electrolytes A and A ′ of the total light received light amount detecting unit A and the ultraviolet light cut received light amount detecting unit B use the same solution as described above, and 3-methyl-p- is used as a quinone. In the total light receiving amount detection unit A, since the total light transmitting plate 16 provided on the surface transmits all light including ultraviolet light, 3-methyl-p-hydroxybenzoquinone and Thus, the amount of 3-methyl-p-benzoquinone decreases. At the same time, the same change is caused by other light rays (for example, infrared rays) or ambient temperature, and the amount thereof is further reduced. On the other hand, in the ultraviolet ray cut received light amount detection unit B, since the ultraviolet ray cut transmitting plate 16 'cuts ultraviolet rays, the influence of ultraviolet rays on 3-methyl-p-benzoquinone is cut off, and 3-methyl-p-benzoquinone is ultraviolet rays. It changes to 3-methyl-p-hydroxybenzoquinone under the influence of conditions other than and decreases. That is, the difference between them is only a decrease in 3-methyl-p-benzoquinone due to ultraviolet rays.
[0056]
When 3-methyl-p-benzoquinone decreases, when the reduction potential of 3-methyl-p-benzoquinone is applied to the first working electrode 10 and the second working electrode 10 ′, the first working electrode 10 and the second working electrode 10 In the vicinity, the reduction current flowing by 3-methyl-p-benzoquinone depriving protons decreases. If the difference in the reduction current value of 3-methyl-p-benzoquinone measured by the total light reception amount detection unit A and the ultraviolet ray cut reception amount detection unit B is calculated, this difference becomes the difference in the reduction current value derived from the ultraviolet rays. Then, the amount of received UV light is measured by comparing the time for receiving UV light with a calibration curve indicating the amount of 3-methyl-p-benzoquinone that has been calibrated in advance for each UV intensity. is there. If the ultraviolet cut transmission plate 16 ′ cannot cut 100% ultraviolet rays, the correction is made according to the blocking rate of the ultraviolet cut transmission plate 16 ′. For example, if the blocking rate is 90%, it is multiplied by 1.03.
[0057]
By the way, in the first embodiment, the potentials of the first working electrode 10 and the second working electrode 10 ′ are swept in order to measure the reduction current. However, other types of voltage application methods other than sweeping are also effective. Therefore, the two application methods including the sweeping method will be described in a little more detail.
[0058]
The first application method is the method already used in the first embodiment, and the first counter electrode 11 or the second counter electrode 11 ′ is set to, for example, +800 mV to the first comparison electrode 12 or the second comparison electrode 12 ′. This is a method of sweeping in the range of −1000 mV. Although the voltage range to be swept is selected so as not to be affected by dissolved oxygen, it should be noted that it varies depending on the type of each electrode and the type of quinone. This method is called voltammetry. FIG. 4 is an explanatory diagram of the reduction current that appears when voltammetry is performed. As shown in FIG. 4, in the case of voltammetry, the peak value of the reduction current that appears in the potential-reduction current curve (voltamogram) obtained as a result of the sweep is measured. The sweep rate is suitably 10 mV / s to 200 mV / s so that the electrode reaction is controlled by electron transfer.
[0059]
In the second application method, the reduction potential of 3-methyl-p-benzoquinone is applied to the first counter electrode 11 or the second counter electrode 11 ′ in a pulsed or stepped manner with respect to the first comparison electrode 12 or the second comparison electrode 12 ′. It is the method of applying to. Although it depends on the kind of quinone, it is appropriate to select a quinone that is in the range of -200 mV to -1000 mV because of the relationship with the absorption of ultraviolet rays. This voltage range is a range not affected by dissolved oxygen. Note that this range slightly varies when the first working electrode 10 or the second working electrode 10 'is made of a material different from the carbon material as described above. This application method is called chronoamperometry. When chronoamperometry is performed, an electric double layer is formed on the surface of the first working electrode 10 or the second working electrode 10 ', and a phenomenon occurs in which quinone anionizes in the vicinity of the electrode and takes protons from the solvent. In this Embodiment 1, since 3-methyl-p-benzoquinone is used, it is reduced by electron transfer and hydrolyzed to 3-methyl-p-hydroxybenzoquinone. The reduction current that flows suddenly at this time is called the Faraday current, which is proportional to the amount of 3-methyl-p-benzoquinone. By measuring this Faraday current value, the amount of 3-methyl-p-benzoquinone is reversed. It can be measured. FIG. 5 is an explanatory diagram of the Faraday current that appears when chronoamperometry is performed.
[0060]
The ultraviolet sensor and the measuring chip in the first embodiment measure the reduction current value by the electrochemical method described above, calculate the amount of ultraviolet rays, and display the ultraviolet irradiation amount on the display unit. The specific control circuit and operation will be described.
[0061]
First, a measuring chip C is attached to a part of the body in order to measure the amount of received UV light, and the first light transmitting window 13 of the total light received light amount detecting unit A and the second light transmitting window 13 ′ of the UV cut received light amount detecting unit B. To point in the direction of the sun. After being exposed to sunlight for a certain period of time, the measurement chip C is removed from the body and inserted into the measurement chip insertion portion 6 of the main body 1. Thereby, each electrode and the control circuit in the main body 1 are electrically connected. Therefore, the power button 5 is pressed to activate the ultraviolet sensor. Further, the start button 3 is pressed to start the measurement. FIG. 6 is a control circuit diagram of the ultraviolet sensor according to the first embodiment. In FIG. 6, reference numeral 35 denotes an LCD as one of the display units 2, and 36 denotes a control unit that controls the ultraviolet sensor, which includes a microcomputer and includes a memory. The control unit 36 performs control for applying a predetermined potential to each electrode of the measurement chip C, and also controls the LCD 35. The calculation unit 48, which will be described later, measures the total light received light amount detection unit A and the ultraviolet ray cut light reception amount detection unit B. The amount of ultraviolet rays is calculated from the peak value of the reduced current.
[0062]
When the start button 3 and the power button 5 are pressed, the control unit 36 turns on the switch in the corresponding circuit, and the ultraviolet sensor becomes operable. Then, the control unit 36 first causes the total light received light amount detection unit A to start detecting the received light amount, and when this is finished, the ultraviolet cut received light amount detection unit B detects the received light amount of the light whose ultraviolet rays have been cut. To
[0063]
Reference numeral 37 denotes a D / D that converts data output from the control unit 36 into an analog signal to apply a predetermined potential to the first comparison electrode 12, the second comparison electrode 12 ', the first counter electrode 11, and the second counter electrode 11'. A converter, 38 is an operational amplifier that applies a predetermined potential to the first counter electrode 11 or the second counter electrode 11 ′, 39 is a relay that switches the output to the first comparison electrode 12 and the second comparison electrode 12 ′, and 40 is the first counter electrode 11 and a relay for switching the output to the second counter electrode 11 '. Reference numeral 41 denotes a D / A converter that converts the data output from the control unit 36 into an analog signal in order to apply a predetermined potential for measuring a reduction current to the first working electrode 10 and the second working electrode 10 '. Reference numeral 43 denotes an operational amplifier that applies a predetermined potential for measuring a reduction current to the first working electrode 10 and the second working electrode 10 ', and 44 denotes between the first working electrode 10 and the first counter electrode 11, and the second working electrode 10'. And a resistor 45 for measuring the current flowing between the first working electrode 10 and the second working electrode 10 '. A voltage amplifying unit 46 receives a voltage drop generated at both ends of the resistor 44 and amplifies it by a differential amplifier circuit constituted by an operational amplifier, and 47 converts the voltage dropped by the voltage amplifying unit 46 into data. The A / D converter is input to the control unit 36. The resistor 44 and the voltage amplification unit 46 are the detection unit of the first embodiment. In the first embodiment, by switching the relays 39, 40, and 45, the first detector that detects the current flowing between the first working electrode 10 and the first counter electrode 11, the second working electrode 10 ′, The circuit can be simplified because it can also be used as a second detector for detecting the current flowing between the two counter electrodes 11 '. Similarly, in the first embodiment, the output voltages of the D / A converters 37 and 41 can be made variable according to the data from the control unit 36, so that the first working electrode 10 and the first counter electrode 11 and the second working electrode 10 '. And the second counter electrode 11 ′ can be different voltages as well as equal voltages. The controller 36 stores the detected data in the internal memory as a current value flowing between the first working electrode 10 and the first counter electrode 11 and between the second working electrode 10 'and the second counter electrode 11'. Reference numeral 48 denotes a calculation unit which takes the difference between the reduction current values measured by the total light received light amount detection unit A and the ultraviolet light cut received light amount detection unit B, and compares it with the stored calibration curve data of ultraviolet rays. To calculate the amount of received UV light.
[0064]
Next, how the control circuit of the first embodiment operates will be described. The measurement chip C is inserted into the measurement chip insertion portion 6 of the main body 1 and activated by pressing the power button 5. Further, when the start button 3 is pressed to start the measurement, the control unit 36 turns on each switch of the corresponding control circuit to enable the ultraviolet sensor. Next, the control unit 36 instructs the total light reception amount detection unit A to start detection of the received light amount. In order to measure the reduction current value of 3-methyl-p-benzoquinone by all rays including sunlight (sunlight), the control unit 36 needs to energize the first counter electrode 11, the first working electrode, and the first comparison electrode 12. The relay 40 is connected to the A ′ contact side, the relay 39 is connected to the A ′ ″ contact side, and the relay 45 is connected to the A ″ side. Thereafter, the control unit 36 reads the data for the first comparison electrode 12 from the memory, The analog signal is input to the operational amplifier 38 by the D / A converter 37. The operational amplifier 38 controls the potential applied to the first counter electrode 11 using the imaginary short so that the first comparison electrode becomes the reference voltage according to the data. At the same time, the control unit 36 reads data for the first working electrode 10 from the memory, converts it to analog by a D / A converter, and inputs it to the operational amplifier 43. The operational amplifier 4 Is a follower in order to prevent a voltage drop from occurring in the resistor 44 for detecting the current and a change in the potential of the first working electrode 10 on the output side. Thus, it is controlled to a predetermined potential.
[0065]
In Embodiment 1, since the voltammetry is performed in order to detect the light irradiation amount of the total light reception amount detection unit A, the control unit 36 sets the potential of the first working electrode 10 to a sweep speed of 10 mV / s to 200 mV / s, +800 mV. Sweep in the range of -1000 mV. The first counter electrode 11 is applied with an imaginary short circuit of the operational amplifier 38 so that the first working electrode 10 has a predetermined potential to be swept when the potential of the first comparison electrode 12 is used as a reference. At this time, the value of the reduction current flowing through the first working electrode 10 is detected by a voltage drop by the resistor 44, amplified by the voltage amplifier 46, converted into data via the A / D converter 47, and input to the controller 36. The controller 36 selects and memorizes the peak value data among the data constituting the voltammogram from the current value data. This data is the deterioration data for 3-methyl-p-benzoquinone of the total light reception amount detection unit A.
[0066]
Subsequently, the control unit 36 instructs the ultraviolet ray cut received light amount detection unit B to detect the received light amount of light whose ultraviolet rays have been cut. The detection of the amount of received light by the ultraviolet ray cut received light amount detection unit B is the same as the detection by the total light reception amount detection unit A described above. In order to measure the reduction current of 3-methyl-p-benzoquinone by the light from which the ultraviolet rays are cut, the control unit 36 needs to energize the second counter electrode 11 ′, the second working electrode 10 ′, and the second comparison electrode 12 ′. The relay 40 is connected to the B ′ contact side, the relay 39 is connected to the B ′ ″ contact side, and the relay 45 is connected to the B ″ side. Thereafter, the control unit 36 reads the data for the second comparison electrode 12 ′ from the memory, The signal is converted into an analog signal by the D / A converter 37 and input to the operational amplifier 38. The operational amplifier 38 controls the potential applied to the second counter electrode 11 'using the imaginary short so that the second comparison electrode becomes the reference voltage according to the data. Further, the control unit 36 reads out data for the second working electrode 10 'from the memory, converts it to analog by a D / A converter, and inputs it to the operational amplifier 43. 43 is a follower in order to prevent a voltage drop caused by a resistor 44 for detecting a current and a change in the potential of the second working electrode 10 'on the output side. The control unit 36 sweeps the potential of the second working electrode 10 'within a sweep speed of 10 mV / s to 200 mV / s and a range of +800 mV to -1000 mV. When the second working electrode 10 ′ is based on the potential of the second comparison electrode 12 ′, a potential that becomes a sweep potential is applied to the second counter electrode 11 ′ by an imaginary short circuit of the operational amplifier 38. The reduction current value flowing through the working electrode 10 ′ is detected by a voltage drop by the resistor 44, amplified by the voltage amplifier 46, converted into data via the A / D converter 47, and input to the controller 36. The control unit 36 selects and memorizes the peak value data among the data constituting the voltammogram from the current value data, and this data is stored in the 3-methyl-p-benzoquinone of the ultraviolet ray cut received light amount detection unit B. It is degradation data for.
[0067]
When the control unit 36 obtains the deterioration data for the 3-methyl-p-benzoquinone of the total light reception amount detection unit A and the deterioration data for the 3-methyl-p-benzoquinone of the total light reception amount detection unit A, the calculation unit 48. Is compared with the stored calibration curve of ultraviolet rays to calculate the amount of received ultraviolet rays.
[0068]
In the first embodiment described above, the control unit 36 obtains the peak value of the reduction current by voltammetrically measuring the amount of ultraviolet rays. However, the Faraday current is measured by the above-mentioned chronoamperometry to measure the ultraviolet rays. The amount of received light can also be calculated. In this case, the control unit 36 sets the relay 40 to the A ′ contact, the relay 45 to the A ″ contact, and the relay 39 to the A ′ ″ contact, and applies a pulsed or stepped voltage to the first working electrode 10. At this time, the value of the reduction current flowing through the first working electrode 10 is detected by the resistor 44, converted into data via the voltage amplification unit 46 and the A / D converter 47, and input to the control unit 36. The control unit 36 stores data on the current value. The control unit 36 switches the relay 40 to the B ′ contact, the relay 45 to the B ″ contact, and the relay 39 to the B ′ ″ contact to select the second working electrode. A 10 'pulse or step voltage is applied. The reduction current value flowing at this time is detected by the resistor 44, converted into data via the voltage amplifier 46 and the A / D converter 47, and input to the controller 36. The control unit 36 selects and memorizes data that is regarded as a Faraday current from the current value data. The calculation unit 48 can calculate the amount of ultraviolet rays from these data by comparing with a calibration curve for the amount of ultraviolet irradiation stored in advance.
[0069]
As described above, the ultraviolet sensor according to the first embodiment measures the irradiation amount of all rays by voltammetry, measures the irradiation amount of light excluding the ultraviolet rays, and takes the difference between the two irradiation amounts. It is possible to calculate the amount of ultraviolet rays irradiated to the. Moreover, the amount of ultraviolet rays irradiated to the measuring chip can be measured in a short time by performing chronoamperometry.
[0070]
【The invention's effect】
The ultraviolet ray measuring chip according to the present invention is Equipped with a total light reception amount detection unit and an ultraviolet cut light reception amount detection unit, and measures the two of the stored quinone that has been reduced by UV irradiation and the one that does not decrease, and calculates the difference between the two. Since the irradiation amount is calculated, it can be measured with a small amount of reagent, can be operated in a compact and simple manner, is easy to carry, and can measure the amount of ultraviolet rays with high accuracy regardless of the length of the light receiving time.
[0071]
Further, the ultraviolet ray measuring chip according to the present invention is Since the total light transmission plate contains quartz glass, it transmits 99% or more of ultraviolet rays without blocking light of other frequencies and is inexpensive.
[0072]
Further, the ultraviolet ray measuring chip according to the present invention is Since the ultraviolet cut transmission plate is equipped with an ultraviolet cut filter, only ultraviolet rays can be cut without blocking light of other frequencies.
[0073]
Further, the ultraviolet ray measuring chip according to the present invention is Since the first working electrode and the second working electrode are each composed of one or more materials selected from carbon, glassy carbon, and gold, the current value can be measured stably.
[0074]
Further, the ultraviolet ray measuring chip according to the present invention is Since the first counter electrode and the second counter electrode are made of a corrosion-resistant conductor, they can be measured stably without deterioration.
[0075]
Further, the ultraviolet ray measuring chip according to the present invention is Since the corrosion-resistant conductor is composed of one or more materials selected from platinum, stainless steel, platinum-containing alloys, and carbon, deterioration is caused. Almost And stable measurement.
[0076]
Further, the ultraviolet ray measuring chip according to the present invention is Since the first reference electrode and the second comparison electrode are each made of gold or carbon, the comparison electrode is simple and inexpensive.
[0077]
The ultraviolet sensor according to the present invention is A measurement chip insertion portion for inserting an ultraviolet measurement chip is provided, and when the ultraviolet measurement chip is inserted, the potential between the first working electrode and the first comparison electrode is swept and between the second working electrode and the second comparison electrode. A control unit that sweeps the potential; a first detection unit that detects a current flowing between the first working electrode and the first counter electrode; and a second detection unit that detects a current flowing between the second working electrode and the second counter electrode. It has a calculation unit that calculates the amount of ultraviolet rays from the difference between the current values detected by the first detection unit and the second detection unit, so it can be measured with a small amount of reagent, is compact and easy to operate, and is easy to carry Therefore, it is possible to measure the amount of ultraviolet rays with high accuracy regardless of the length of the light receiving time.
[0078]
The ultraviolet sensor according to the present invention is And a measurement chip insertion portion for inserting the ultraviolet measurement chip, and when the ultraviolet measurement chip is inserted, the gap between the first working electrode and the first comparison electrode is controlled to a predetermined potential with reference to the first comparison electrode. A control unit that controls a predetermined potential between the second working electrode and the second comparison electrode with reference to the second comparison electrode; a first detection unit that detects a current flowing between the first working electrode and the first counter electrode; A second detection unit that detects a current flowing between the second working electrode and the second counter electrode, and a calculation unit that calculates an ultraviolet ray amount from a difference between currents detected by the first detection unit and the second detection unit. Therefore, it is possible to measure with a small amount of reagent, it is compact and easy to operate, the control part is simpler, it is easy to carry, and it can measure the amount of ultraviolet rays with high accuracy regardless of the length of light reception time. .
[0079]
Furthermore, the ultraviolet sensor according to the present invention is Since the second power supply and the first power supply are shared, the power supply circuit becomes compact.
[0080]
Furthermore, the ultraviolet sensor according to the present invention is Since the controller sweeps at a sweep speed of 10 mV / s to 200 mV / s, the pre-peak value of the current can be measured with high accuracy.
[0081]
The ultraviolet ray measuring method according to the present invention is In addition to irradiating the coexisting electrolyte containing quinone, organic solvent and electrolyte with total light, irradiating the coexisting electrolyte containing quinone, organic solvent and electrolyte with ultraviolet light, Since the amount of ultraviolet rays is calculated by voltammetrically measuring the coexisting electrolytes that have been irradiated with light from which ultraviolet rays have been cut and taking the difference in reduction current, it is possible to easily measure with a small amount of reagent and to measure the amount of ultraviolet rays with high accuracy. .
[0082]
Moreover, the ultraviolet ray measuring method according to the present invention includes: The coexisting electrolyte containing quinone, organic solvent, and electrolyte is irradiated with all light, and the coexisting electrolyte containing quinone, organic solvent, and electrolyte is irradiated with ultraviolet light, and the coexisting electrolyte and ultraviolet light irradiated with all light. Since the amount of ultraviolet rays is calculated by chronoamperometry of each coexisting electrolyte that has been irradiated with light cut off and taking the difference in reduction current, it can be measured more easily and quickly with a small amount of reagent, and the accuracy is high The amount of ultraviolet rays can be measured.
[Brief description of the drawings]
FIG. 1 is a schematic external view of an ultraviolet sensor according to Embodiment 1 of the present invention.
FIG. 2 is an explanatory diagram of an ultraviolet ray measuring chip of the ultraviolet ray sensor according to Embodiment 1 of the present invention.
FIG. 3 is a graph showing the relationship between the irradiation time of light to the quinone-containing coexisting electrolyte and the peak value of the quinone reduction current.
FIG. 4 is an explanatory diagram of a reduction current that appears when voltammetry is performed.
FIG. 5 is an explanatory diagram of Faraday current that appears when chronoamperometry is performed.
FIG. 6 is a control circuit diagram of the ultraviolet sensor in the first embodiment.
[Explanation of symbols]
1 body
2 display section
3 Start button
3 'Start switch
4 Mode switching button
4 'Mode selector switch
5 Power button
6 Measuring tip insertion part
7 First working electrode pattern
7 Second working electrode pattern
7t1 Terminal for first working electrode
7t2 Terminal for second working electrode
8 Pattern for first counter electrode
8 'Second counter electrode pattern
8t1 Terminal for first counter electrode
8t2 Terminal for second counter electrode
9 Pattern for first reference electrode
9 'Second reference electrode pattern
9t1 Terminal for first reference electrode
9t2 Terminal for second reference electrode
10 First working electrode
10 'second working electrode
11 First counter electrode
11 'second counter electrode
12 First reference electrode
12 'second reference electrode
13 First light transmission window
13 'second light transmission window
14 First reaction chamber
14 'Second reaction chamber
15 Substrate
16 Total light transmission plate
16 'UV cut transmission plate
35 LCD
36 Control unit
37,41 D / A converter
38,43 operational amplifier
39, 40, 45 Relay
44 Resistance
46 Voltage amplifier
47 A / D converter
48 Calculation unit

Claims

An ultraviolet ray measuring method using an ultraviolet ray measuring chip provided with a total light received light amount detecting unit and an ultraviolet ray cut received light amount detecting unit, and an ultraviolet sensor into which the ultraviolet ray measuring chip is inserted,
The ultraviolet ray measuring chip is
The total light receiving amount detection unit contains a quinone, an organic solvent, and an electrolyte-containing coexisting electrolytic solution, and is provided in the first reaction chamber provided with the first light transmission window and the first light transmission window. A total light transmissive plate, a first working electrode disposed in the first reaction chamber and immersed in the coexisting electrolyte, and a first counter electrode;
  The ultraviolet ray cut received light amount detection unit accommodates a quinone, organic solvent, and electrolyte-containing coexisting electrolyte, and is provided in a second reaction chamber provided with a second light transmission window and in the second light transmission window. An ultraviolet cut transmission plate, a second working electrode disposed in the second reaction chamber and immersed in the coexisting electrolyte, and a second counter electrode;
  A plurality of terminals electrically connected to the first working electrode, the first counter electrode, the second working electrode, and the second counter electrode,
The ultraviolet sensor is
A measuring chip insertion portion provided with a connector terminal that can be electrically connected to each of the terminals,
  A first power source capable of applying a voltage between the first working electrode and the first counter electrode when the ultraviolet measuring chip is inserted; a second power source capable of applying a voltage between the second working electrode and the second counter electrode; Have
  A first detector for detecting a current flowing between the first working electrode and the first counter electrode; a second detector for detecting a current flowing between the second working electrode and the second counter electrode;
A calculation unit that calculates a difference between the reduction current values detected by the first detection unit and the second detection unit;
An ultraviolet ray measuring method, wherein the ultraviolet ray amount is measured based on the difference between the reduction current values.

2. The ultraviolet ray measuring method according to claim 1, wherein the ultraviolet ray measuring chip has a total light transmitting plate containing quartz glass.

3. The ultraviolet ray measuring method according to claim 1, wherein the ultraviolet ray measuring chip has an ultraviolet ray cut transmitting plate provided with an ultraviolet ray cut filter.

4. The ultraviolet ray measuring chip, wherein the first working electrode and the second working electrode are each made of one or more materials selected from carbon, glassy carbon, and gold. The ultraviolet-ray measuring method in any one of.

5. The ultraviolet measurement method according to claim 1, wherein the first counter electrode and the second counter electrode are each made of a corrosion-resistant conductor. 5.

6. The ultraviolet ray measuring method according to claim 5, wherein the ultraviolet ray measuring chip is made of one or more materials selected from platinum, stainless steel, a platinum-containing alloy, and carbon.