JPH0471460B2 - - Google Patents
Info
- Publication number
- JPH0471460B2 JPH0471460B2 JP61168645A JP16864586A JPH0471460B2 JP H0471460 B2 JPH0471460 B2 JP H0471460B2 JP 61168645 A JP61168645 A JP 61168645A JP 16864586 A JP16864586 A JP 16864586A JP H0471460 B2 JPH0471460 B2 JP H0471460B2
- Authority
- JP
- Japan
- Prior art keywords
- heat
- circuit
- voltage
- pair
- temperature
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Landscapes
- Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)
Description
【発明の詳細な説明】
産業上の利用分野
本発明は、一対の電極間に試料穀物を挟み、そ
の間に電位差を与えて流れる電流信号から試料穀
物の水分を測定する装置に関するものである。DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a device that measures the moisture content of a sample grain from a current signal flowing by sandwiching a sample grain between a pair of electrodes and applying a potential difference between the electrodes.
従来の技術
従来、この種の穀物の水分測定装置は、例え
ば、実公昭56−41247号公報に記載されているが、
この装置においては、一対の電極ロールが抵抗を
直列にして定電圧電源に接続されていて、一対の
電極ロール間に試料穀物が挟まれた際に、その間
に流れる電流信号を抵抗の端子間電圧として検出
し、試料穀物の水分を測定するようになつてい
る。BACKGROUND ART Conventionally, this type of grain moisture measuring device has been described in, for example, Japanese Utility Model Publication No. 1983-41247.
In this device, a pair of electrode rolls is connected to a constant voltage power supply with a resistor in series, and when a sample grain is sandwiched between the pair of electrode rolls, the current signal flowing between them is converted into a voltage across the terminals of the resistor. It is now designed to detect and measure the moisture content of sample grains.
発明が解決しようとする問題点
ところで、一般に試料穀物の水分に対する電気
抵抗の幅は、数キロオームから数100メガオーム
にも及ぶので、上記のような従来の水分測定装置
においては、一対の電極ロールに直列に挿入する
抵抗値を、高低２段階以上に切り換えて測定レン
ジを切り換えなければならず、測定装作が煩雑で
あり、不便であるばかりでなく、水分測定を自動
的に行うものでは、そのために測定回路が複雑に
なる等の問題点が指摘されている。Problems to be Solved by the Invention Incidentally, the electrical resistance of sample grains to moisture generally ranges from several kiloohms to several hundred megaohms, so in the conventional moisture measuring device as described above, a pair of electrode rolls It is necessary to change the measurement range by changing the resistance value inserted in series to two or more high and low levels, which not only makes the measurement equipment complicated and inconvenient, but also makes it difficult to measure moisture automatically. Problems such as the complexity of the measurement circuit have been pointed out.
本発明は、このような問題点に鑑み、測定レン
ジの切り換えを行わずに、試料穀物の水分を全範
囲に亙つて外気温度変化にかかわらず高い精度で
測定ることができる穀物の水分測定装置を提供す
ることを目的とするものである。 In view of these problems, the present invention provides a grain moisture measuring device that is capable of measuring the moisture content of sample grains over the entire range with high accuracy regardless of outside temperature changes without changing the measurement range. The purpose is to provide the following.
問題点を解決するための手段
本発明は、その目的に達成するための技術的手
段を次のように構成した。Means for Solving the Problems The present invention has the following technical means for achieving the object.
すなわち、本発明に係る穀物の水分測定装置
は、一対の電極間に試料穀物を挟み、その間に電
位差を与えて流れる電流信号から試料穀物の水分
を測定する装置において、高抵抗と低抵抗それぞ
れに電圧対電流の関係が対数特性を有するダイオ
ードを直列接続し、かつそれらを並列接続したも
のを一対の電極と定電圧電源の回路中に直列接続
し、上記一方の抵抗の端子間電圧から試料穀物の
水分を検出する回路を構成するとともに、正の温
度係数をもつ感熱抵抗体とその発熱のための電力
供給回路からなる前記ダイオードを一定温度に保
つための保温装置を設けたことを特徴とするもの
である。 That is, the grain moisture measuring device according to the present invention is a device that measures the moisture content of a sample grain from a current signal flowing by sandwiching a sample grain between a pair of electrodes and applying a potential difference between them. Diodes having a logarithmic relationship between voltage and current are connected in series, and these are connected in parallel to a pair of electrodes and a constant voltage power supply circuit, and the sample grain is determined from the voltage between the terminals of one of the resistors. In addition to configuring a circuit for detecting moisture, the diode is also provided with a heat-retaining device for keeping the diode at a constant temperature, which is composed of a heat-sensitive resistor having a positive temperature coefficient and a power supply circuit for generating heat from the heat-sensitive resistor. It is something.
作 用
一対の電極と定電圧電源との間には、高低の抵
抗をそれぞれ電圧対電流の関係が対数特性を有す
るダイオードを介して前記のように接続してある
ので、このダイオードの対数特性によつて、高水
分レンジから低水分レンジに至るなだらかな端子
間電圧の出力形成され、しかも、ダイオードは保
温装置により一定の温度に保たれるので、その特
性は外気温度の変化にかかわらず変動しない。こ
のため、試料穀物の水分測定にあたつては、高水
分から低水分のものに至るまで、測定レンジの切
り換えを行わずに、判別するのに十分な値の端子
間電圧を検出することができる。Function: As described above, high and low resistances are connected between the pair of electrodes and the constant voltage power supply through diodes whose voltage-to-current relationship has logarithmic characteristics. Therefore, a gradual voltage output between the terminals is formed from the high moisture range to the low moisture range, and since the diode is kept at a constant temperature by the insulation device, its characteristics do not change regardless of changes in the outside temperature. . Therefore, when measuring the moisture content of sample grains, it is possible to detect a voltage across the terminals with a sufficient value to distinguish between high moisture and low moisture without having to switch the measurement range. can.
実施例 本発明の実施例を図面について説明する。Example Embodiments of the present invention will be described with reference to the drawings.
第１図は本発明に係る装置の基本回路を示して
おり、１，１′は一対の電極ロール、２は定電圧
電源であつて、一対の電極ロール１，１′は定電
圧電源２に検出回路３を介して直列に接続されて
いる。この検出回路３は、低抵抗R1、高抵抗R2
にそれぞれ電圧対電流の関係が対数特性を有する
素子としてダイオードD1，D2を順方向直列に接
続し、かつこれらを並列に接続したものである。
４はオペアンプであつて、上記高抵抗R2の端子
間電圧ｅはこのオペアンプ４で増幅され、出力電
圧e′が得られるようになつている。なお、対数特
性を有する素子としては、ダイオードD1，D2の
ほかトランジスタその他の半導体素子を使用する
ことができる。ダイオードD1，D2は特性のよく
揃つたものを用いることが望ましい。 FIG. 1 shows the basic circuit of the device according to the present invention, where 1 and 1' are a pair of electrode rolls, 2 is a constant voltage power source, and the pair of electrode rolls 1 and 1' are connected to the constant voltage power source 2. They are connected in series via a detection circuit 3. This detection circuit 3 has a low resistance R 1 and a high resistance R 2
Diodes D 1 and D 2 are connected in series in the forward direction as elements having logarithmic characteristics in the relationship between voltage and current, and these are connected in parallel.
4 is an operational amplifier, and the voltage e between the terminals of the high resistance R2 is amplified by the operational amplifier 4 to obtain an output voltage e'. Note that as the elements having logarithmic characteristics, in addition to the diodes D 1 and D 2 , transistors and other semiconductor elements can be used. It is desirable to use diodes D 1 and D 2 with well-matched characteristics.
一般に、ダイオードの順電圧VFと順電流IFの
関係は、VF＝１＋bLogIFであり、対数特性を有
する。そこで、検出回路３における低抵抗R1と
ダイオードD1および高抵抗R2とダイオードD2を
直列にした部分の両端の電圧は、
R1・I1＋ａ＋bLogI1＝R2・I2＋ａ＋bLogI2
……
I1／I2＝ｍとすると式より
I2＝bLogm／（R2−mR1） ………
Ｉ＝I1＋I2であるから、
Ｉ＝（１＋ｍ）I2 ………
、式より、
Ｉ／（１＋ｍ）＝bLogm／（R2−mR1）
……
となり、Ｉとｍとの関係式中にはダイオード特性
のａが現れない。なお、Ｉ，I1，I2は第１図に示
した回路の当該部分の電流である。 Generally, the relationship between forward voltage VF and forward current IF of a diode is VF=1+bLogIF, and has logarithmic characteristics. Therefore, the voltage across the part where low resistance R 1 and diode D 1 and high resistance R 2 and diode D 2 are connected in series in the detection circuit 3 is R 1・I 1 +a+bLogI 1 =R 2・I 2 +a+bLogI 2
...... If I 1 / I 2 = m, then from the formula I 2 = bLogm / (R 2 - mR 1 ) ...... I = I 1 + I 2 , so I = (1 + m) I 2 ......, formula From, I/(1+m)=bLogm/(R 2 −mR 1 )
..., and the diode characteristic a does not appear in the relational expression between I and m. Note that I, I 1 , and I 2 are currents in the relevant portions of the circuit shown in FIG.
上記の式からｍとＩとがわかれば、高抵抗
R2側の電流I2が求められる。第２図には、ｍを
1.1〜97まで変えた場合の電流ＩとI2の関係が示
されている。この図から明らかなように、電流Ｉ
が0.01〜1000μAと10万倍変化しても、電流I2は
0.005〜10μAと2000倍で小さく、少ない電流変化
で大きい電流変化を検出できる。第３図には、第
１図の回路において、一対の電極１，１′に挟ま
れた試料穀物の電気抵抗Ｚに対する出力電圧ｅと
の関係が示されている。この図に示されている高
水分レンジおよび低水分レンジ線は、第７図の従
来例において、抵抗R1，R2をスイツチで切り変
えた場合の特性であるが、第１図のように構成し
た本発明のもので、高抵抗R2を従来例の２倍と
すると、ちようど両ライン間をなだらかに結ぶカ
ーブの特性となるので、測定レンジ切り換えるこ
となく、高水分から抵水分までの測定ができるこ
とになる。なお、第２図および第３図に示された
特性は、次の回路条件の下における計算値および
実測値である。 If m and I are known from the above equation, high resistance
The current I 2 on the R 2 side is determined. In Figure 2, m is
The relationship between current I and I 2 when varying from 1.1 to 97 is shown. As is clear from this figure, the current I
Even if the current changes by a factor of 100,000 from 0.01 to 1000 μA, the current I2 remains
It is 2000 times smaller at 0.005 to 10 μA, and can detect large current changes with small current changes. FIG. 3 shows the relationship between the output voltage e and the electrical resistance Z of the sample grain sandwiched between the pair of electrodes 1 and 1' in the circuit of FIG. The high moisture range and low moisture range lines shown in this figure are the characteristics when the resistances R 1 and R 2 are changed by a switch in the conventional example shown in Fig. 7, but as shown in Fig. 1, With the structure of the present invention, if the high resistance R 2 is twice that of the conventional example, the characteristic will be a curve that gently connects both lines, so you can measure from high moisture to low moisture without changing the measurement range. This means that it is possible to measure The characteristics shown in FIGS. 2 and 3 are calculated values and actually measured values under the following circuit conditions.
ダイオード特性：
VF（mV）＝512＋65.6LogIF（μA）
抵 抗：
R1＝4.7（ＫΩ）、R2＝470（ＫΩ）
定電圧電源の電圧：
15000（mV）
本発明に係る装置は、第１図に示すものを基本
回路として、さらに、第４図に示すように構成さ
れる。すなわち、第１図に示された回路中のダイ
オードD1，D2を常に一定の温度（例えば50℃）
に保つための保温装置５を備えており、ダイオー
ドD1，D2の温度による特性変化を無くし、測定
精度の向上を図るようになつている。６は熱源で
あつて、この熱源６はダイオードD1，D2を共に
加温するものである。熱源６は第５図に示すよう
に正の温度係数をもつ感熱抵抗体７およびそれに
通電して発熱させるための電力供給回路８からな
り、ダイオードD1，D2と感熱抵抗体７は一体に
パツケージされている。このように正の温度係数
をもつ感熱抵抗体７を発熱体とすれば、温度が上
昇すれば発熱量が減じ、温度が下降すれば発熱量
が増すので、これが温度センサを兼ねたものとな
つて簡素な構成となる。 Diode characteristics: VF (mV) = 512 + 65.6LogIF (μA) Resistance: R 1 = 4.7 (KΩ), R 2 = 470 (KΩ) Voltage of constant voltage power supply: 15000 (mV) The device according to the present invention The basic circuit shown in FIG. 1 is further configured as shown in FIG. 4. That is, the diodes D 1 and D 2 in the circuit shown in Figure 1 are always kept at a constant temperature (for example, 50°C).
It is equipped with a heat insulating device 5 to keep the diodes D 1 and D 2 at a constant temperature, thereby eliminating changes in the characteristics of the diodes D 1 and D 2 due to temperature, thereby improving measurement accuracy. 6 is a heat source, and this heat source 6 heats both the diodes D 1 and D 2 . As shown in FIG. 5, the heat source 6 consists of a heat-sensitive resistor 7 having a positive temperature coefficient and a power supply circuit 8 for energizing it to generate heat, and the diodes D 1 , D 2 and the heat-sensitive resistor 7 are integrated. Packaged. If the heat-sensitive resistor 7, which has a positive temperature coefficient, is used as a heating element, the amount of heat generated decreases when the temperature rises, and increases when the temperature falls, so it doubles as a temperature sensor. This results in a simple configuration.
第６図には熱源６の他例が示されている。９は
熱源６の発熱体７′を加熱するための電力増幅回
路、１０は温度検出回路、１１は温度センサ、１
２は温度設定回路、１３は比較器であつて、熱源
６の温度を温度検出回路１０の温度センサ１１で
検出し、温度設定回路１２で設定した温度を保つ
ように電力増幅回路９を制御するように構成され
ている。 Another example of the heat source 6 is shown in FIG. 9 is a power amplifier circuit for heating the heating element 7' of the heat source 6; 10 is a temperature detection circuit; 11 is a temperature sensor;
2 is a temperature setting circuit, and 13 is a comparator, which detects the temperature of the heat source 6 with a temperature sensor 11 of a temperature detection circuit 10 and controls the power amplifier circuit 9 to maintain the temperature set by the temperature setting circuit 12. It is configured as follows.
第４図および第６図の構成においては、前記第
１図のものと同様に作動するが、ダイオードD1，
D2が常に一定の温度に保たれるので、外気温度
の変化による測定誤差が生ぜず、測定精度は著し
く向上する。 The configurations shown in FIGS. 4 and 6 operate in the same manner as in FIG. 1, but the diodes D 1 ,
Since D 2 is always kept at a constant temperature, measurement errors due to changes in outside temperature do not occur, and measurement accuracy is significantly improved.
発明の効果
本発明は、前記のように、一対の電極間に試料
穀物を挟み、その間に電位差を与えて流れる電流
信号から試料穀物の水分を測定する装置におい
て、高抵抗と低抵抗それぞれに電圧対電流の関係
が対数特性を有するダイオードを直列接続し、か
つそれらを並列接続したものを一対の電極と定電
圧電源の回路中に直列接続し、上記一方の抵抗の
端子間電圧から試料穀物の水分を検出する回路を
構成するとともに、正の温度係数をもつ感熱抵抗
体とその発熱のための電力供給回路からなる前記
ダイオードを一定温度に保つための保温装置を設
けたことを特徴とするものであるから、通常数キ
ロオームから数100メガオームにも及び広範囲の
測定レンジに亙り、しかも外気温度の影響を受け
やすい殻物の水分測定を、測定レンジを切り換え
ることなく全範囲に亙り、しかも外気温度の影響
を受けることなく高い精度を保つて行うことがで
き、測定操作が簡便となるだけでなく、自動測定
を行うものにおいては、その構成の簡素化と測定
の信頼性の向上を図ることができる。Effects of the Invention As described above, the present invention provides an apparatus for measuring the moisture content of a sample grain from a current signal flowing by sandwiching a sample grain between a pair of electrodes and applying a potential difference between them. Diodes having a logarithmic current relationship are connected in series, and these are connected in parallel to a pair of electrodes and a constant voltage power supply circuit, and the voltage between the terminals of one of the resistors is determined by A device comprising a circuit for detecting moisture, and further comprising a heat-retaining device for keeping the diode at a constant temperature, which is composed of a heat-sensitive resistor having a positive temperature coefficient and a power supply circuit for generating heat. Therefore, it is possible to measure the moisture content of shells over a wide range of measurement ranges, usually from several kiloohms to several hundred megaohms, and which is susceptible to the influence of outside temperature. This not only simplifies the measurement operation but also simplifies the configuration and improves the reliability of measurements for automatic measurements. can.
第１図ないし第６図は本発明の実施例を示し、
第１図は本発明に係る装置の基本回路図、第２図
および第３図はその作用説明図、第４図は本発明
に係る装置の回路図、第５図および第６図はそれ
ぞれ第４図のものの一部の構成図である。また、
第７図は従来例を示した回路図である。
１，１′…一対の電極、２…定電圧電源、３…
検出回路、４…オペアンプ、５…保温装置、６…
熱源、７…感熱抵抗体、７′…発熱体、８…電力
供給回路、９…電力増幅回路、１０…温度検出回
路、１１…温度センサ、１２…温度設定回路、１
３…比較器、R1，R2…抵抗、D1，D2…ダイオー
ド。
1 to 6 show embodiments of the present invention,
FIG. 1 is a basic circuit diagram of the device according to the present invention, FIGS. 2 and 3 are explanatory diagrams of its operation, FIG. 4 is a circuit diagram of the device according to the present invention, and FIGS. 5 and 6 are respective diagrams. 4 is a configuration diagram of a part of the one shown in FIG. 4. FIG. Also,
FIG. 7 is a circuit diagram showing a conventional example. 1, 1'...pair of electrodes, 2...constant voltage power supply, 3...
Detection circuit, 4... operational amplifier, 5... heat retention device, 6...
Heat source, 7... Heat sensitive resistor, 7'... Heating element, 8... Power supply circuit, 9... Power amplifier circuit, 10... Temperature detection circuit, 11... Temperature sensor, 12... Temperature setting circuit, 1
3...Comparator, R1 , R2 ...Resistor, D1 , D2 ...Diode.
Claims (1)
位差を与えて流れる電流信号から試料穀物の水分
を測定する装置において、高抵抗と低抵抗それぞ
れに電圧対電流の関係が対数特性を有するダイオ
ードを直列接続し、かつそれらを並列接続したも
のを一対の電極と定電圧電源の回路中に直列接続
し、上記一方の抵抗の端子間電圧から試料穀物の
水分を検出する回路を構成するとともに、正の温
度係数をもつ感熱抵抗体とその発熱のための電力
供給回路からなる前記ダイオードを一定温度に保
つための保温装置を設けたことを特徴とする穀物
の水分測定装置。1 In a device that measures the moisture content of a sample grain from a current signal flowing by sandwiching a sample grain between a pair of electrodes and applying a potential difference between them, diodes with a logarithmic voltage-to-current relationship are used for high resistance and low resistance, respectively. A pair of electrodes and a constant voltage power supply circuit are connected in series, and these are connected in parallel to form a circuit that detects the moisture content of the sample grain from the voltage between the terminals of one of the resistors. 1. A grain moisture measuring device comprising a heat-retaining device for keeping the diode at a constant temperature, which is composed of a heat-sensitive resistor having a temperature coefficient of 1 and a power supply circuit for generating heat.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16864586A JPS6325543A (en) | 1986-07-17 | 1986-07-17 | Moisture measuring apparatus for grain |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16864586A JPS6325543A (en) | 1986-07-17 | 1986-07-17 | Moisture measuring apparatus for grain |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6325543A JPS6325543A (en) | 1988-02-03 |
| JPH0471460B2 true JPH0471460B2 (en) | 1992-11-13 |
Family
ID=15871874
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP16864586A Granted JPS6325543A (en) | 1986-07-17 | 1986-07-17 | Moisture measuring apparatus for grain |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6325543A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5989171B1 (en) * | 2015-03-31 | 2016-09-07 | 三菱電機株式会社 | CURRENT DETECTION CIRCUIT AND ELECTRIC CONTROL DEVICE FOR VEHICLE HAVING THE CIRCUIT |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6076657A (en) * | 1983-10-03 | 1985-05-01 | Matsushita Electric Ind Co Ltd | Humidity detecting device |
-
1986
- 1986-07-17 JP JP16864586A patent/JPS6325543A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6325543A (en) | 1988-02-03 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US3731189A (en) | Pulse sampling resistance metering method and means | |
| WO2018127793A1 (en) | Devices and methods for smart sensor application | |
| US4818977A (en) | Combustible gas detector having temperature stabilization capability | |
| US3973147A (en) | Temperature measuring circuit | |
| US5265459A (en) | Single-element thermal conductivity detector | |
| US3540283A (en) | Temperature sensor | |
| JP2810541B2 (en) | Lambda sensor internal resistance measurement circuit | |
| US3319155A (en) | Electrical calibration device for strain gage bridges | |
| US3196682A (en) | Humidity sensing circuit | |
| US3964315A (en) | Apparatus including novel bridge circuit | |
| JPH0471460B2 (en) | ||
| US5096303A (en) | Electronic circuit arrangement for temperature measurement based on a platinum resistor as a temperature sensing resistor | |
| US3646436A (en) | Apparatus and method for measuring electrical resistance employing constant output voltage technique | |
| Lacey et al. | An improved potentiometric circuit for measuring the galvanic skin response | |
| JP3310479B2 (en) | Grain moisture meter | |
| JPH0516527Y2 (en) | ||
| US3478588A (en) | Cardiac output meter | |
| SU1597596A1 (en) | Electronic temperature-sensitive element | |
| JPH0624747Y2 (en) | Temperature / voltage conversion circuit | |
| SU1717975A1 (en) | Circuit for measurement of radiation | |
| SU469106A1 (en) | Device for stabilizing parameters of devices based on the use of the hall effect | |
| JPS593319A (en) | Liquid level detector | |
| Zolik et al. | A transistor psychogalvanometer | |
| SU805200A1 (en) | Resistance meter | |
| JPS5810136Y2 (en) | Electric resistance grain moisture meter |