JPS5920658Y2 - Detection circuit for thermal conduction type vacuum gauge - Google Patents
Detection circuit for thermal conduction type vacuum gaugeInfo
- Publication number
- JPS5920658Y2 JPS5920658Y2 JP1267883U JP1267883U JPS5920658Y2 JP S5920658 Y2 JPS5920658 Y2 JP S5920658Y2 JP 1267883 U JP1267883 U JP 1267883U JP 1267883 U JP1267883 U JP 1267883U JP S5920658 Y2 JPS5920658 Y2 JP S5920658Y2
- Authority
- JP
- Japan
- Prior art keywords
- gauge
- detection circuit
- enclosed
- vacuum gauge
- conduction type
- 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
Links
Landscapes
- Measuring Fluid Pressure (AREA)
Description
【考案の詳細な説明】
本考案は測定誤差の少ない熱伝導型真空ゲージの検出回
路に関する。[Detailed Description of the Invention] The present invention relates to a detection circuit for a thermally conductive vacuum gauge with little measurement error.
ピラニゲージ、サーミスタゲージ等の熱伝導型真空ゲー
ジにおいては従来例えば第１図に示すような検出回路か
゛用いられている。2. Description of the Related Art Conventionally, a detection circuit as shown in FIG. 1 has been used in thermally conductive vacuum gauges such as Pirani gauges and thermistor gauges.
同図において１は測定用開放ゲージ、２は補償用封入ゲ
ージ、３，４は抵抗、５は測定用メータ、６は定電圧電
源である。In the figure, 1 is an open gauge for measurement, 2 is an enclosed gauge for compensation, 3 and 4 are resistors, 5 is a measurement meter, and 6 is a constant voltage power source.
斯かる構成において測定用メータ５には封入ゲジ２と開
放ゲージ１との圧力差に対応した電流が流れ、圧力を測
定することができる。In such a configuration, a current corresponding to the pressure difference between the enclosed gauge 2 and the open gauge 1 flows through the measuring meter 5, and the pressure can be measured.
ところがこの様な従来の検出回路ではブリッジの平衡が
くずれてＰ点の電圧が上昇することによりメータ５を流
れる電流が封入ゲージ２に流れ、この電流により発生し
た熱が該封入ゲージ２自身の抵抗値を変化させ、測定系
の基準を変化させてしまう。However, in such a conventional detection circuit, when the balance of the bridge is lost and the voltage at point P rises, the current flowing through the meter 5 flows to the enclosed gauge 2, and the heat generated by this current increases the resistance of the enclosed gauge 2 itself. This changes the value and changes the reference of the measurement system.
そのため測定誤差が生ずる結果となっていた。This resulted in measurement errors.
本考案は上述した従来の問題点に鑑みてなされたもので
あり、差動増幅器を用いた簡単な構成で誤差の少ない検
出回路を提供することを目的とする。The present invention was devised in view of the above-mentioned conventional problems, and an object of the present invention is to provide a detection circuit with a simple configuration using a differential amplifier and with little error.
以下図面を用いて本考案を詳説する。第２図は本考案の
一実施例を示す構成図であり、同図において７は十分な
高利得を持った差動増幅器である。The present invention will be explained in detail below using the drawings. FIG. 2 is a block diagram showing an embodiment of the present invention, and in the figure, 7 is a differential amplifier having a sufficiently high gain.
該増幅器７の出力端子と反転入力端子の間には測定用開
放ゲージ１が接続されて負帰還回路を構成し、又、該反
転入力端子とアース間には補償用封入ゲージ２及び抵抗
１０が直列に接続されている。An open measuring gauge 1 is connected between the output terminal and the inverting input terminal of the amplifier 7 to form a negative feedback circuit, and a compensating sealed gauge 2 and a resistor 10 are connected between the inverting input terminal and the ground. connected in series.
更に増幅器７の非反転入力端子は人力抵抗８を介して一
端子が接地された定電圧電源６の子端子に接続されてお
り、該子端子と前記増幅器７の出力端子間には表示用電
圧計９が接続されている。Further, the non-inverting input terminal of the amplifier 7 is connected via a human resistor 8 to a child terminal of a constant voltage power supply 6, one terminal of which is grounded, and a display voltage is connected between the child terminal and the output terminal of the amplifier 7. A total of 9 are connected.
斯かる構成において増幅器７の出力電圧■。In such a configuration, the output voltage of amplifier 7 ■.
は下式で表わされる。is expressed by the following formula.
■ｏ−（１＋Ｒ１／Ｒ２）ｖｉ・・・・・・（１）ここ
でＲ１は開放ゲージ１の抵抗値、Ｒ２は封入ゲージ２と
抵抗１０の直列抵抗値、Ｖｉは定電圧電源６の出力電圧
である。■o-(1+R1/R2)vi...(1) Here, R1 is the resistance value of open gauge 1, R2 is the series resistance value of sealed gauge 2 and resistor 10, and Vi is the output of constant voltage power supply 6. It is voltage.
そのため電圧計９の両端子間にはＶ。Therefore, V is present between both terminals of voltmeter 9.
−Ｖｉ−（Ｒ＋／ Ｒ２） Ｖｉなる電圧が印加される
ことになる。-Vi-(R+/R2) A voltage Vi will be applied.
従って圧力に応じた開放ゲージ１の抵抗値Ｒ１の変化を
電圧計９より読取ることできる。Therefore, the change in the resistance value R1 of the open gauge 1 according to the pressure can be read from the voltmeter 9.
しかも高利得の差動増幅器の性質上補償用封入ゲージ２
に加わる電圧はＶｉで一定となるため測定の基準となる
Ｒ２は変化せず誤差が発生することはなく、従って正確
な測定が可能となる。Moreover, due to the nature of the high-gain differential amplifier, the enclosed gauge 2 for compensation is
Since the voltage applied to V is constant at Vi, R2, which is the reference for measurement, does not change and no error occurs, making accurate measurement possible.
又本考案では抵抗１０を封入ゲージに直列接続している
ため、何らかの原因で万一封入ゲージ２の温度が変化し
て抵抗値が増減し、該封入ゲージ２に流れる電流が減増
すると、抵抗１０による電圧降下が減増して該ゲージ２
に印加される電圧が増減し、それによって該ゲージ２の
発熱が増減されて温度が元に戻るという負帰還の効果が
得られる。In addition, in the present invention, the resistor 10 is connected in series with the enclosed gauge, so if the temperature of the enclosed gauge 2 changes for some reason and the resistance value increases or decreases, and the current flowing through the enclosed gauge 2 decreases or increases, the resistance will change. 10 decreases and increases the voltage drop due to the gauge 2.
A negative feedback effect is obtained in which the voltage applied to the gauge 2 increases or decreases, thereby increasing or decreasing the heat generated by the gauge 2, and the temperature returns to its original value.
尚上述した実施例では電圧計９の一端を電源６の子端子
に接続したが、これに限らず一端子即ちアースに接続し
てもよいことは言うまでもない。In the above-described embodiment, one end of the voltmeter 9 is connected to the child terminal of the power source 6, but it goes without saying that the connection is not limited to this and may be connected to one terminal, that is, the ground.
第１図は従来の検出回路を示す構成図、第２図は本考案
の一実施例を示す構成図である。
１：測定用開放ゲージ、２：補償用封入ゲージ、６：定
電圧電源、７：差動増幅器、９：表示用電圧計、１０：
抵抗。FIG. 1 is a block diagram showing a conventional detection circuit, and FIG. 2 is a block diagram showing an embodiment of the present invention. 1: Open gauge for measurement, 2: Enclosed gauge for compensation, 6: Constant voltage power supply, 7: Differential amplifier, 9: Voltmeter for display, 10:
resistance.
Claims (1)
型真空ゲージと、上記測定用開放ゲージが負帰還回路に
挿入されると共に反転入力端子とアース間に上記補償用
封入ゲージと抵抗が直列に接続された差動増幅器と、該
差動増幅器の非反転入力端子とアース間に接続される定
電圧電源と、上記差動増幅器の出力電圧を測定するため
の手段とから構成されることを特徴とする熱伝導型真空
ゲ゛−ジの検出回路。A thermally conductive vacuum gauge including an open gauge for measurement and an enclosed gauge for compensation; the open gauge for measurement is inserted into a negative feedback circuit, and the enclosed gauge for compensation and a resistor are connected in series between the inverting input terminal and ground. , a constant voltage power supply connected between the non-inverting input terminal of the differential amplifier and ground, and means for measuring the output voltage of the differential amplifier. Features a thermal conduction type vacuum gauge detection circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1267883U JPS5920658Y2 (en) | 1983-01-31 | 1983-01-31 | Detection circuit for thermal conduction type vacuum gauge |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1267883U JPS5920658Y2 (en) | 1983-01-31 | 1983-01-31 | Detection circuit for thermal conduction type vacuum gauge |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5927432U JPS5927432U (en) | 1984-02-20 |
| JPS5920658Y2 true JPS5920658Y2 (en) | 1984-06-15 |
Family
ID=30144074
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1267883U Expired JPS5920658Y2 (en) | 1983-01-31 | 1983-01-31 | Detection circuit for thermal conduction type vacuum gauge |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5920658Y2 (en) |
-
1983
- 1983-01-31 JP JP1267883U patent/JPS5920658Y2/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5927432U (en) | 1984-02-20 |
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