JPH0726885B2 - Low pressure gauge - Google Patents
Low pressure gaugeInfo
- Publication number
- JPH0726885B2 JPH0726885B2 JP63280954A JP28095488A JPH0726885B2 JP H0726885 B2 JPH0726885 B2 JP H0726885B2 JP 63280954 A JP63280954 A JP 63280954A JP 28095488 A JP28095488 A JP 28095488A JP H0726885 B2 JPH0726885 B2 JP H0726885B2
- Authority
- JP
- Japan
- Prior art keywords
- float
- liquid
- pressure
- low
- light
- 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
- 239000007788 liquid Substances 0.000 claims description 37
- 230000003287 optical effect Effects 0.000 claims description 15
- 230000002093 peripheral effect Effects 0.000 claims description 3
- 238000006073 displacement reaction Methods 0.000 claims description 2
- 238000005259 measurement Methods 0.000 description 17
- QSHDDOUJBYECFT-UHFFFAOYSA-N mercury Chemical compound [Hg] QSHDDOUJBYECFT-UHFFFAOYSA-N 0.000 description 15
- 229910052753 mercury Inorganic materials 0.000 description 15
- 239000012530 fluid Substances 0.000 description 14
- 230000000694 effects Effects 0.000 description 7
- 238000000034 method Methods 0.000 description 5
- 238000001514 detection method Methods 0.000 description 3
- 230000010287 polarization Effects 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 230000005484 gravity Effects 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 230000002411 adverse Effects 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 230000002238 attenuated effect Effects 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000010291 electrical method Methods 0.000 description 1
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 239000010931 gold Substances 0.000 description 1
- 238000009499 grossing Methods 0.000 description 1
- 230000001678 irradiating effect Effects 0.000 description 1
- 238000002955 isolation Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 150000002730 mercury Chemical class 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000005304 optical glass Substances 0.000 description 1
- 238000004544 sputter deposition Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- 238000009736 wetting Methods 0.000 description 1
Landscapes
- Measurement Of Levels Of Liquids Or Fluent Solid Materials (AREA)
- Measuring Fluid Pressure (AREA)
Description
【発明の詳細な説明】 ［産業上の利用分野］ 本発明は、低圧用圧力計に関し、特に実用真空計を10-3
Torr程度の低圧側の測定限界まで、±0.1％の精度で校
正することができる高精度の基準真空計に好適な低圧用
圧力計に関する。TECHNICAL FIELD The present invention relates to a low-pressure pressure gauge, and particularly to a practical vacuum gauge of 10 −3.
The present invention relates to a low-pressure pressure gauge suitable for a high-accuracy reference vacuum gauge that can be calibrated with an accuracy of ± 0.1% up to a low-pressure side measurement limit of about Torr.
［従来の技術］ 従来のこの種の圧力計としては、例えば、第６図に示す
ような白色光を用いてマイケルソン干渉計と水銀Ｕ字管
を組合わせた光波干渉式の標準気圧計（計量研究所報告
VOL24,NO2,p27-p46,'75）がある。第６図において、La,
Lbは光源用ランプ、Ｓはスプリッタ、Ma,Mbは参照鏡、M
cは測微顕微鏡、Ｐは直角プリズム、Ｑは平行プリズ
ム、V1,V2,V3は真空バルブ、GBはブロックゲージ、Ｇは
光学ガラス、Ｔは望遠鏡、Phは光電変換器、Ｂはベッ
ド、Ｃは滑動台、Scは標準尺、Swは微調整ねじ、N1は半
透明鏡、N2,Rは反射鏡である。この標準気圧計は、Ｕ字
管部内の水銀面が光学的に良好な反射面であることか
ら、この水銀面をマイケルソン干渉計の一方の反射面と
して利用し、水銀の液面に垂直に白色光をあてて等厚干
渉によりビームスプリッタＳに対する水銀面までの位置
が、対応する反射鏡Ｒまでの距離に関係づけて光の半波
長以下の測定分解能で原理的には測定可能となるもので
ある。[Prior Art] As a conventional pressure gauge of this type, for example, a standard barometer of a light wave interference type (a Michelson interferometer and a mercury U-shaped tube in combination using white light as shown in FIG. 6 ( Metrology Institute Report
VOL24, NO2, p27-p46, '75). In Fig. 6, La,
Lb is a light source lamp, S is a splitter, Ma and Mb are reference mirrors, M
c is a microscopic microscope, P is a right-angle prism, Q is a parallel prism, V 1 , V 2 and V 3 are vacuum valves, GB is a block gauge, G is an optical glass, T is a telescope, Ph is a photoelectric converter, and B is a photoelectric converter. Bed, C is a slide, Sc is a standard scale, Sw is a fine adjustment screw, N 1 is a semitransparent mirror, and N 2 and R are reflecting mirrors. In this standard barometer, since the mercury surface in the U-shaped tube is an optically good reflecting surface, this mercury surface is used as one reflecting surface of the Michelson interferometer to make it perpendicular to the liquid surface of mercury. In principle, it is possible to measure the position of the light beam splitter S up to the mercury surface due to equal thickness interference by irradiating the white light with the distance to the corresponding reflecting mirror R with a measurement resolution of a half wavelength or less of the light. Is.
このような光波干渉式の外に、水銀面の位置決めには望
遠鏡で水平方向から水銀面を観測する光学的方法や静電
容量で検出するなどの電気的方法があった。例えば、光
学的方法の中では望遠鏡とカセットメータとを組合わせ
て水銀面を水平方向から観測する方法が直接的で精度も
比較的高かったが、望遠長の視野内での標識線合わせの
操作の精度およびＵ字管のガラスの管壁による光の屈折
により測定分解能の限界が10-2Torr台であった。これに
対して、水銀の蒸気圧や床面の振動による水銀液面ゆれ
から理想通りの値は得難いにせよ、上述の光波干渉式の
標準気圧計は他の方式の標準気圧計よりも原理的にはよ
り高精度化を図ることが可能である。In addition to such a light wave interference method, positioning of the mercury surface includes an optical method of observing the mercury surface from a horizontal direction with a telescope and an electrical method such as detection with a capacitance. For example, among the optical methods, the method of observing the mercury surface from the horizontal direction by combining a telescope and a cassette meter was direct and relatively accurate, but the operation of marking line alignment in the telephoto long field of view was performed. Accuracy and the refraction of light by the wall of the glass of the U-shaped tube limits the measurement resolution to the 10 -2 Torr range. On the other hand, although it is difficult to obtain the ideal value from the mercury liquid pressure fluctuation due to mercury vapor pressure and floor vibration, the above-mentioned light wave interference type standard barometer is theoretically more effective than other standard barometers. It is possible to achieve higher accuracy.
［発明が解決しようとする課題］ しかしながら、上記従来の光波干渉式の水銀液柱差真空
計による標準気圧計では、水銀の液面から直接反射する
光で光干渉計を構成しているので、床面からの振動によ
る水銀の液面のゆらぎにより水銀の液面から反射する光
はその光の波面が乱れた上に、かなり減衰するので干渉
縞が不明瞭となり、そのためその液面のゆらぎでその低
圧側の測定限界が決まり、測定分解能が0.7μｍ程で、
その精度が±１％とすれば0.07Torr以下の低圧測定は実
際上困難となる。さらに液面のゆらぎが大きい場合は、
反射光は光検出位置からずれて信号が消滅することもあ
る。また、この測定系に係る上記問題の他に、作動液を
上記のように水銀にすると1Torr以下で蒸気が測定気体
中に混入し、測定不可能になるという低圧用圧力計とし
ては重大な問題点があった。[Problems to be Solved by the Invention] However, in the conventional standard barometer using the above-mentioned conventional light wave interference type mercury liquid column differential vacuum gauge, since the light interferometer is constituted by the light directly reflected from the liquid surface of mercury, The light reflected from the liquid surface of mercury is disturbed by the fluctuation of the liquid surface of mercury caused by the vibration from the floor surface, and the interference fringes become unclear because the light wavefront is considerably attenuated. The measurement limit on the low voltage side is determined, and the measurement resolution is about 0.7 μm,
If the accuracy is ± 1%, it will be practically difficult to measure low pressures below 0.07 Torr. If the fluctuation of the liquid level is large,
The reflected light may be displaced from the light detection position and the signal may disappear. In addition to the above problems related to this measurement system, when the working fluid is mercury as described above, vapor is mixed into the measurement gas at 1 Torr or less, which is a serious problem as a low pressure manometer. There was a point.
本発明は、上記問題点を解決するために、液面の振動を
抑えて平滑化し、作動液の種類にかかわらず、安定で再
現性のよい光波干渉式の低圧用圧力計を提供することを
目的とする。In order to solve the above problems, the present invention provides a stable and reproducible light wave interference type low pressure pressure gauge that suppresses and smoothes the vibration of the liquid surface, regardless of the type of hydraulic fluid. To aim.
［課題を解決するための手段］ 上記目的を達成するため、本発明は、感圧素子として油
等の蒸気圧の低い液体を使用し、該液体の変位を光波干
渉計で計測することにより真空または真空に近い低圧力
を測定する低圧用圧力計であって、前記液体を収納する
受圧管の壁面に対面して複数の対称的な平面、または曲
面からなる周面を有し、かつ該液体以外は非接触となる
フロートを該液体の表面に浮かべ、該フロートの上面全
体を鏡面に形成し、または前記フロートの中心に反射器
を取付けて前記光波干渉計からの入射光を反射するよう
に構成したことを特徴とする。[Means for Solving the Problems] In order to achieve the above object, the present invention uses a liquid having a low vapor pressure such as oil as a pressure-sensitive element, and measures the displacement of the liquid with an optical wave interferometer to obtain a vacuum. Alternatively, a low-pressure pressure gauge for measuring low pressure close to vacuum, which has a peripheral surface composed of a plurality of symmetrical flat surfaces or curved surfaces facing the wall surface of the pressure receiving tube containing the liquid, and the liquid. Other than that, the float which is not in contact is floated on the surface of the liquid, the entire upper surface of the float is formed into a mirror surface, or a reflector is attached to the center of the float so as to reflect the incident light from the light wave interferometer. It is characterized by being configured.
［作用］ 本発明は、フロートで作動液の液面の振動を抑えて平滑
化し、また、反射器または鏡面の反射面が液柱の中心か
らずれて、管壁に近づくと反発して中心位置に復帰する
機能をもつ形状のフロートを組込むことにより光干渉計
システムを構成するようにしたので、次のような作用が
得られる。[Operation] In the present invention, the float suppresses vibration of the liquid surface of the hydraulic fluid to smooth it, and when the reflector or the reflecting surface of the mirror surface deviates from the center of the liquid column and approaches the pipe wall, it repels and the central position. Since the optical interferometer system is configured by incorporating a float having a shape capable of returning to, the following effects can be obtained.
フロートを作動液に浮べるので、作動液の液面の振
動が押えられ、平滑化する。Since the float floats on the hydraulic fluid, the vibration of the hydraulic fluid level is suppressed and smoothed.
反射面は空中にあるので、高い反射率で入射光と同
じ偏光のモードを保ったまま、反射器から反射する。Since the reflecting surface is in the air, it reflects from the reflector while maintaining the same polarization mode as the incident light with high reflectance.
フロートは、その対称形状により液柱の管の中止位
置に自動的に自身の中心を復帰する。Due to its symmetrical shape, the float automatically returns its center to the stop position of the liquid column tube.
このため、フロートの中心に置かれた反射器、また
はフロートの鏡面の位置がずれにくいので、反射光の光
軸が安定する。For this reason, the position of the reflector placed in the center of the float or the mirror surface of the float is unlikely to shift, and the optical axis of the reflected light is stabilized.
これらの作用により、作動液の種類によらないで、安定
で再現性の良い光波干渉式の低圧用圧力計が構成できる
ので、作動液を従来のような蒸気圧の高い水銀を使用す
るという条件に拘束されない。Due to these effects, a stable and reproducible light wave interference type low-pressure pressure gauge can be constructed irrespective of the type of hydraulic fluid. Not be bound by.
従って、本発明によれば高精度の基準真空計を提供する
ことができ、また、この基準真空計を用いて、実用真空
計を10-3Torr程度の低圧側の測定限界まで、±0.1％の
精度で校正することができる等の利点がある。Therefore, according to the present invention, it is possible to provide a high-accuracy reference vacuum gauge, and using this reference vacuum gauge, a practical vacuum gauge up to a measurement limit on the low pressure side of about 10 -3 Torr is ± 0.1%. There is an advantage that it can be calibrated with the accuracy of.
［実施例］ 以下、図面を参照して本発明の実施例を詳細に説明す
る。Embodiments Embodiments of the present invention will be described in detail below with reference to the drawings.
第１図は本発明の一実施例の要部構成を示し、本図
（Ａ）は上方から、本図（Ｂ）は横方向から見た図であ
る。本図において、１は光波干渉式の液柱差真空計のＵ
字管内に実装する比較的比重の軽い液面フロート、２は
フロート１の中心位置に貫通して固設した浮力円筒（フ
ロート本体）、３は円筒２内に配設したコーナキューブ
の如き反射器（反射プリズム）、４は上記Ｕ字管の管
壁、５はＵ字管に封入された作動液（例えば、油）６の
液面、７は円筒２の底部を形成するバランス用のウェイ
ト（おもり）である。FIG. 1 shows the configuration of the main part of an embodiment of the present invention, FIG. 1 (A) being viewed from above and FIG. 1 (B) being viewed laterally. In this figure, 1 is U of a liquid wave differential vacuum gauge of the light wave interference type.
Liquid level float with a relatively low specific gravity to be mounted in a character tube. 2 is a buoyancy cylinder (float body) fixed through the center of the float 1 and 3 is a reflector such as a corner cube arranged in the cylinder 2. (Reflecting prism), 4 is a wall of the U-shaped tube, 5 is a liquid surface of the hydraulic fluid (for example, oil) 6 enclosed in the U-shaped tube, and 7 is a balance weight (which forms the bottom of the cylinder 2). Weight).
フロート１は管壁４に対して向い合う面が複数の対称的
な平面、または凹面（凹形周面）のような曲面を有す
る、例えば第１図または第７図（Ａ）のような星芒形、
あるいは第２図（Ａ）〜（Ｇ）に示すような対称の形状
を有し、そのフロート１を構成する材質として比重が軽
く、かつ作動液６に濡れない物質、またはその材質を濡
らさない作動液６が用いられる。以上の条件を満たせ
ば、作動液６の表面張力がフロート１の各平面、または
曲面に均一に作用するので、フロート１の中心部にある
反射器（反射プリズムまたは鏡面）３の位置は自動的に
Ｕ字管の中心の位置に常に保たれ、光軸から外れにくい
こととなる。The float 1 has a plurality of symmetrical flat surfaces facing the tube wall 4 or curved surfaces such as concave surfaces (concave peripheral surfaces), for example, a star as shown in FIG. 1 or FIG. 7 (A). Awn,
Alternatively, a substance having a symmetrical shape as shown in FIGS. 2 (A) to (G) and having a low specific gravity as a material forming the float 1 and not wet with the hydraulic fluid 6, or an operation not wetting the material Liquid 6 is used. If the above conditions are satisfied, the surface tension of the hydraulic fluid 6 acts uniformly on each flat surface or curved surface of the float 1, so that the position of the reflector (reflection prism or mirror surface) 3 at the center of the float 1 is automatically adjusted. In addition, it is always kept at the center position of the U-shaped tube, and it is difficult for it to come off the optical axis.
また、液面上にフロートを浮べてあるので、フロート１
により床面の振動による液面のゆらぎを抑え、かつ平滑
化する作用がある。このため、フロート１上の反射器３
により第３図（Ａ）に示すように、光軸の安定した、ま
た偏光面の乱れない良質の反射光11が得られ、液面の微
少な振動によって反射光11の波面が乱されることは無
い。Also, because the float floats above the liquid surface, float 1
This has the effect of suppressing the fluctuation of the liquid surface due to the vibration of the floor surface and smoothing it. Therefore, the reflector 3 on the float 1
As a result, as shown in FIG. 3 (A), high-quality reflected light 11 with a stable optical axis and no disturbed polarization plane is obtained, and the wavefront of the reflected light 11 is disturbed by a slight vibration of the liquid surface. There is no.
さらに、液面の直接の反射、または油中にある反射鏡か
らの反射光ではなく、空中にある反射器３からの反射光
を得られるので、入射光10の強度のほぼ80％以上の反射
率の高い反射光が得られる。Furthermore, since the reflected light from the reflector 3 in the air can be obtained instead of the reflected light directly from the liquid surface or the reflected light from the reflecting mirror in the oil, reflection of about 80% or more of the intensity of the incident light 10 can be obtained. Highly reflected light can be obtained.
また、上述の作動液６を水銀にすれば、蒸気圧が高いた
めに、光干渉計自体よりも粗い測定精度しか得られな
い。このため、作動液６として蒸気圧の低い液体、例え
ば油を用い、かつ本発明のフロート１と反射器３を用い
て光干渉計システムを構成した場合には、低圧側の限界
は10-3Torrで±0.1％の高精度の低圧用圧力計が実現で
きる。Further, if the above-mentioned hydraulic fluid 6 is mercury, the vapor pressure is high, so that only coarser measurement accuracy can be obtained than the optical interferometer itself. Therefore, when an optical interferometer system is configured by using a liquid having a low vapor pressure as the hydraulic fluid 6, for example, oil and using the float 1 and the reflector 3 of the present invention, the lower limit of the low pressure side is 10 -3. Torr can realize a high-precision low-pressure pressure gauge of ± 0.1%.
第７図（Ａ），（Ｂ）は本発明の他の実施例を示す。本
図において、2Aは第１図の浮力円筒２の代りに、フロー
ト１の表面側に形成した浮力穴である。この浮力穴2Aは
主としてバランスを保つため、例えばフロート１の中心
に対して同一円周上で放射状に等間隔にして複数形成さ
れる。なお、浮力穴2Aの代りに同心円のリング状、また
は放射状の複数の溝（浮力溝）であってもよい。FIGS. 7A and 7B show another embodiment of the present invention. In this figure, 2A is a buoyancy hole formed on the surface side of the float 1 instead of the buoyancy cylinder 2 of FIG. The buoyancy holes 2A are mainly formed in order to maintain balance, and for example, a plurality of buoyancy holes 2A are formed at equal intervals radially on the same circumference with respect to the center of the float 1. Instead of the buoyancy holes 2A, concentric ring-shaped or radial grooves (buoyancy grooves) may be used.
また、コーナーキューブの如き反射器３はフロート１の
中心位置に開口した穴の内部に配置され、その穴の底は
前述したバランス用のウエイト７が固定される。A reflector 3 such as a corner cube is arranged inside a hole opened at the center of the float 1, and the balance weight 7 described above is fixed to the bottom of the hole.
なお、上述の浮力穴2Aはフィルム状のもので密封しても
好ましい。また、反射器３を配設した穴も測定光に悪影
響を与えない透明フィルムや透明ガラスで密封すること
も考えられる。第７図の実施例の作用効果は上述した第
１図の実施例の場合とほぼ同様であるが、第１図の円筒
２のような上下方向の検出部分が無くなってフロートの
全体の形状がより単純化して平らな板状となったので、
その製造，組立て，調整，保存，計測時の取扱い等がよ
り容易となる利点がある。The above-mentioned buoyancy hole 2A is preferably film-shaped and may be hermetically sealed. It is also conceivable to seal the hole in which the reflector 3 is arranged with a transparent film or transparent glass that does not adversely affect the measurement light. The operation and effect of the embodiment shown in FIG. 7 are almost the same as those of the embodiment shown in FIG. 1 described above, but there is no vertical detection portion like the cylinder 2 in FIG. Since it is a simpler and flat plate,
It has the advantage that it is easier to manufacture, assemble, adjust, store, and handle during measurement.
第８図（Ａ），（Ｂ）は本発明のさらに他の実施例を示
す。本実施例は、第７図の実施例の作用効果をより強調
した一例であり、フロート１の形状を管壁４の中心部の
みを活用するために18mm×18mm程度に小型化するととも
にその厚みを30μｍ程に薄くした。また、反射器の代り
にフロートの上面全体を鏡面3Aとした。この鏡面3Aはフ
ロート１の基板の反射面に金，アルミを、例えばスパッ
タリングでコートして形成する。このときの反射光線の
光路は第３図（Ｂ）に示すようになる。本実施例は低圧
側の測定の限界に近い用途に適する。FIGS. 8A and 8B show still another embodiment of the present invention. This embodiment is an example in which the function and effect of the embodiment of FIG. 7 are further emphasized, and the shape of the float 1 is reduced to about 18 mm × 18 mm in order to utilize only the central portion of the tube wall 4, and the thickness thereof is reduced. Was thinned to about 30 μm. Also, instead of the reflector, the entire upper surface of the float is a mirror surface 3A. The mirror surface 3A is formed by coating the reflecting surface of the substrate of the float 1 with gold or aluminum, for example, by sputtering. The optical path of the reflected light beam at this time is as shown in FIG. This embodiment is suitable for applications close to the measurement limit on the low pressure side.
第４図および第５図は、第１図，第７図または第８図の
本発明実施例のフロート１を用いた液柱差圧力計の測長
部分の構成例を示す。本図において、Ｕ字管21内の作動
液６の表面にそれぞれ第１図，第７図または第８図に示
すようなフロート１を浮かべ、タンク22を介して一方を
真空にし、他方に被測定気体を与えている。FIG. 4 and FIG. 5 show a structural example of the length measuring part of the liquid column differential pressure gauge using the float 1 of the embodiment of the present invention shown in FIG. 1, FIG. 7 or FIG. In this figure, float 1 as shown in FIG. 1, FIG. 7 or FIG. 8 is floated on the surface of hydraulic fluid 6 in U-shaped tube 21, one is evacuated through tank 22, and the other is covered. Giving measurement gas.
本液柱差圧力計を搭載する防振台23上のレーザー光源24
から出射されたレーザービームは、下部のミラー25、お
よび光学ベンチ26に設けた上方のミラー27を通り、ビー
ムスプリッタ28、およびミラー29を介して、上方から垂
直に上述のＵ字管21内の両方のフロート１に達し、フロ
ート１上のコーナーキューブ（反射器）３で入射光と同
じ方向で数ミリ平行移動した光軸を通って反射するか、
またはフロート１の上面全体にコートされた金属の鏡面
3Aにより入射光は鏡面反射される（第３図（Ａ），
（Ｂ）参照）。Laser light source 24 on a vibration isolation table 23 equipped with this liquid column differential pressure gauge
The laser beam emitted from the laser beam passes through the lower mirror 25 and the upper mirror 27 provided on the optical bench 26, passes through the beam splitter 28, and the mirror 29, and vertically in the above-mentioned U-shaped tube 21. It reaches both floats 1 and is reflected by a corner cube (reflector) 3 on the float 1 through an optical axis that is translated several millimeters in the same direction as the incident light,
Or a mirror surface of metal coated on the entire upper surface of float 1
Incident light is specularly reflected by 3A (Fig. 3 (A),
(See (B)).
30はＵ字管21の排気を行う排気系、31は上述の被測定気
体である。その他の構成は第６図の従来例と同様なの
で、その詳細な説明は省略する。Reference numeral 30 is an exhaust system for exhausting the U-shaped pipe 21, and 31 is the gas to be measured. The other structure is the same as that of the conventional example shown in FIG. 6, and a detailed description thereof will be omitted.
［発明の効果］ 以上説明したように、本発明によれば、従来のように直
接作動液の反射光を利用するものでは反射効率が悪く、
かつ入射光の偏光モードの乱れなどにより測定精度が十
分に得られなかったのを、液面フロートを浮べるフロー
ト式にして液面の振動を抑制し、平滑化するようにし、
かつフロートの中心に位置する反射器、またはフロート
に形成した鏡面が自動的に管壁に触れない位置へ復帰す
るようにしたので、反射光の方向が規定の許容範囲内に
安定して収まり、液面を直接読み取る方式に比べて安定
性の良い測長結果が得られるという効果がある。このた
め、本発明によれば測定分解能0.01μｍ以下の高精度の
測定が実際上可能となる。[Effects of the Invention] As described above, according to the present invention, the reflection efficiency is poor in the conventional device that directly uses the reflected light of the working fluid,
And because the measurement accuracy could not be obtained sufficiently due to the disturbance of the polarization mode of the incident light, the float type that floats the liquid surface float is used to suppress the vibration of the liquid surface and smooth it,
And since the reflector located in the center of the float or the mirror surface formed on the float automatically returns to a position where it does not touch the tube wall, the direction of the reflected light is stably within the specified tolerance range, Compared with the method of directly reading the liquid level, it has the effect of obtaining stable measurement results. Therefore, according to the present invention, highly accurate measurement with a measurement resolution of 0.01 μm or less is practically possible.
第１図（Ａ）は本発明実施例の要部構成を示す平面図、 第１図（Ｂ）はその正面図、 第２図（Ａ）〜（Ｇ）はそれぞれ本発明に好適なフロー
トの形状の一例を示す平面図、 第３図（Ａ），（Ｂ）は第１図（Ｂ），第７図（Ｂ）お
よび第８図（Ｂ）の反射器（コーナーキューブ）、また
はフロート上面全体に形成された鏡面に対する入射光と
反射光の光路を示す光路図、 第４図は本発明実施例の液柱差圧力計の測長部分の構成
例を示す正面図、 第５図はその右側面図、 第６図は従来の標準気圧計の構成例を示す構成図、 第７図（Ａ）は本発明の他の実施例の要部構成を示す平
面図、 第７図（Ｂ）はその平面図、 第８図（Ａ）は本発明のさらに他の実施例の要部構成を
示す平面図、 第８図（Ｂ）はその平面図である。 １……フロート、２……浮力円筒（フロート本体）、2A
……浮力穴、３……反射器（反射プリズム、コーナキュ
ーブ）、3A……鏡面、４……管壁、５……液面、６……
作動液（例えば、油）、７……ウェイト（おもり）、10
……入射光、11……反射光、21……Ｕ字管。FIG. 1 (A) is a plan view showing the configuration of the main part of an embodiment of the present invention, FIG. 1 (B) is a front view thereof, and FIGS. 2 (A) to (G) are floats suitable for the present invention. A plan view showing an example of the shape, FIGS. 3 (A) and 3 (B) are the reflector (corner cube) of FIG. 1 (B), FIG. 7 (B) and FIG. 8 (B), or the upper surface of the float. FIG. 4 is an optical path diagram showing the optical paths of incident light and reflected light with respect to the entire mirror surface, FIG. 4 is a front view showing a configuration example of the length measuring portion of the liquid column differential pressure gauge of the embodiment of the present invention, and FIG. Right side view, FIG. 6 is a configuration diagram showing a configuration example of a conventional standard barometer, FIG. 7 (A) is a plan view showing a configuration of a main part of another embodiment of the present invention, and FIG. 7 (B). Is a plan view thereof, FIG. 8 (A) is a plan view showing a main part configuration of still another embodiment of the present invention, and FIG. 8 (B) is a plan view thereof. 1 ... Float, 2 ... Buoyancy cylinder (float body), 2A
...... Buoyancy hole, 3 ...... Reflector (reflection prism, corner cube), 3A ...... Mirror surface, 4 ...... Tube wall, 5 ...... Liquid level, 6 ......
Hydraulic fluid (eg oil), 7 ... weight (weight), 10
…… Incident light, 11 …… Reflected light, 21 …… U-shaped tube.
Claims (1)
使用し、該液体の変位を光波干渉計で計測することによ
り真空または真空に近い低圧力を測定する低圧用圧力計
であって、 前記液体を収納する受圧管の壁面に対面して複数の対称
的な平面、または曲面からなる周面を有し、かつ該液体
以外は非接触となるフロートを該液体の表面に浮かべ、 該フロートの上面全体を鏡面に形成し、または前記フロ
ートの中心に反射器を取付けて前記光波干渉計からの入
射光を反射するように構成したことを特徴とする低圧用
圧力計。1. A low-pressure pressure gauge for measuring a vacuum or a low pressure close to a vacuum by using a liquid having a low vapor pressure such as oil as a pressure-sensitive element, and measuring the displacement of the liquid with an optical wave interferometer. A plurality of symmetrical flat surfaces facing the wall surface of the pressure receiving tube that stores the liquid, or having a peripheral surface formed of a curved surface, and floating a non-contact float other than the liquid on the surface of the liquid, A low-pressure pressure gauge, characterized in that the entire upper surface of the float is formed into a mirror surface, or a reflector is attached to the center of the float to reflect incident light from the light wave interferometer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63280954A JPH0726885B2 (en) | 1988-02-08 | 1988-11-07 | Low pressure gauge |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2688488 | 1988-02-08 | ||
| JP63-26884 | 1988-02-08 | ||
| JP63280954A JPH0726885B2 (en) | 1988-02-08 | 1988-11-07 | Low pressure gauge |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01295127A JPH01295127A (en) | 1989-11-28 |
| JPH0726885B2 true JPH0726885B2 (en) | 1995-03-29 |
Family
ID=26364735
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63280954A Expired - Lifetime JPH0726885B2 (en) | 1988-02-08 | 1988-11-07 | Low pressure gauge |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0726885B2 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100449149B1 (en) * | 2002-11-04 | 2004-09-18 | 한국표준과학연구원 | Small Pressure Generation And Measurement Device |
| US7062967B2 (en) * | 2003-07-08 | 2006-06-20 | Daimlerchrysler Corporation | Fuel level sensor |
| JP4617660B2 (en) * | 2003-10-28 | 2011-01-26 | 株式会社島津製作所 | Turbo rotating equipment |
-
1988
- 1988-11-07 JP JP63280954A patent/JPH0726885B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH01295127A (en) | 1989-11-28 |
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