JPS6314784B2 - - Google Patents
Info
- Publication number
- JPS6314784B2 JPS6314784B2 JP55123970A JP12397080A JPS6314784B2 JP S6314784 B2 JPS6314784 B2 JP S6314784B2 JP 55123970 A JP55123970 A JP 55123970A JP 12397080 A JP12397080 A JP 12397080A JP S6314784 B2 JPS6314784 B2 JP S6314784B2
- Authority
- JP
- Japan
- Prior art keywords
- measured
- resistor
- voltmeter
- cable
- constant current
- 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
- 238000005259 measurement Methods 0.000 claims description 27
- 230000015654 memory Effects 0.000 claims description 18
- 230000005284 excitation Effects 0.000 claims description 16
- 238000010586 diagram Methods 0.000 description 6
- 230000035945 sensitivity Effects 0.000 description 3
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R27/00—Arrangements for measuring resistance, reactance, impedance, or electric characteristics derived therefrom
- G01R27/02—Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant
- G01R27/08—Measuring resistance by measuring both voltage and current
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Measurement Of Resistance Or Impedance (AREA)
Description
【発明の詳細な説明】
本発明は３線式抵抗体測定において、接続する
ケーブル抵抗の影響を補償して測定する抵抗体測
定装置の改良に関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a resistor measuring device that compensates for the influence of connected cable resistance in three-wire resistor measurement.
第１図にケーブル抵抗補償のない３線式抵抗体
測定装置の一例のブロツク図を示す。同図におい
て、励振電源としての定電流値Ｉなる定電流回路
２の一方の出力端と他方の出力端は、３線式抵抗
体測定装置１の接続端子ａとｃにそれぞれ接続さ
れ、この接続端子ａとｃに各基端が接続されたケ
ーブル抵抗（または内部抵抗）ｒを有する第１お
よび第２のケーブルの各先端には、それぞれＲな
る抵抗値を有する被測定抵抗体（以下、被測定体
と略記する。）の一端および他端が接続されてい
る。 FIG. 1 shows a block diagram of an example of a three-wire resistor measuring device without cable resistance compensation. In the figure, one output terminal and the other output terminal of a constant current circuit 2 having a constant current value I as an excitation power source are respectively connected to connection terminals a and c of a three-wire resistance measuring device 1. A resistor to be measured (hereinafter referred to as a resistor to be measured) having a resistance value R is connected to each tip of the first and second cables having a cable resistance (or internal resistance) r whose base ends are connected to terminals a and c. (abbreviated as measurement object) is connected at one end and the other end.
そして、第１のケーブルの基端には、同様に接
続端子ａを介して電圧計３の一方の入力端が接続
され、被測定体の他端には、第１、第２のケーブ
ルと同等（電気的特性が同じで長さが等しい）の
第３のケーブルおよび接続端子ｂを介して電圧計
３の他方の入力端が接続されている。被測定体か
ら入力電圧ｅを受ける電圧計３の出力端には、そ
の測定電圧ｅを抵抗値表示する表示器４が接続さ
れている。 Similarly, one input end of the voltmeter 3 is connected to the base end of the first cable via the connection terminal a, and a cable equivalent to the first and second cables is connected to the other end of the object to be measured. The other input end of the voltmeter 3 is connected via a third cable (having the same electrical characteristics and the same length) and the connection terminal b. A display 4 that displays the measured voltage e as a resistance value is connected to the output end of the voltmeter 3 that receives an input voltage e from the object to be measured.
まずケーブル抵抗ｒ＝０の時、ｅは(1)式にな
る。 First, when cable resistance r=0, e becomes equation (1).
ｅ＝Ｒ・Ｉ ……(1)
(1)式よりＲを求めると(2)式が求まり、電圧計３
でｅを測定して、その結果を表示器４を介して抵
抗値表示すればよい。 e=R・I...(1) When R is calculated from equation (1), equation (2) is obtained, and voltmeter 3
It is sufficient to measure e and display the result as a resistance value on the display 4.
Ｒ＝ｅ／Ｉ ……(2)
しかし実際には、被測定体Ｒと測定装置１の接
続端子ａ，ｂ，ｃ間にはケーブル抵抗ｒが介在し
て測定している。 R=e/I (2) However, in reality, a cable resistance r is interposed between the object to be measured R and the connection terminals a, b, and c of the measuring device 1 during measurement.
ケーブル抵抗ｒが入つた時の電圧計３の入力電
圧をe1とすると、次に示す(3)式のようになる。 If the input voltage of the voltmeter 3 when the cable resistance r is included is e1 , then the following equation (3) is obtained.
e1＝（Ｒ＋2r）Ｉ−ｒ・Ｉ＝Ｒ・Ｉ＋ｒ・Ｉ
……(3)
(3)式よりＲを求めると(4)式が得られる。 e 1 = (R+2r)I-r・I=R・I+r・I
...(3) When R is determined from equation (3), equation (4) is obtained.
Ｒ＝e1／Ｉ−ｒ ……(4)
(4)式よりケーブル抵抗ｒによつて、真の抵抗値
Ｒよりｒ分大きく表示されて、測定誤差が生じ
る。 R=e 1 /I−r (4) From equation (4), depending on the cable resistance r, the true resistance value R is displayed larger by r, resulting in a measurement error.
そこでこのケーブル抵抗ｒを補償するためのバ
ランス回路を内蔵した従来からある一例のブロツ
ク図を第２図に示す。 FIG. 2 shows a block diagram of a conventional example that includes a built-in balance circuit to compensate for this cable resistance r.
第２図は、演算増幅器５のプラス入力が３の出
力に、マイナス入力が可変抵抗器VRに、演算増
幅器５の出力が表示器４に接続されている点が異
なるだけで、他はすべて第１図と同様の構成であ
る。 The only difference in Figure 2 is that the positive input of operational amplifier 5 is connected to output 3, the negative input is connected to variable resistor VR, and the output of operational amplifier 5 is connected to display 4. The configuration is similar to that in Figure 1.
(4)式のｒに相当する電圧分を、演算増幅器５の
マイナス入力に印加するように基準電圧Ｖから、
VRを調整してケーブル抵抗ｒをバランス調整し
ているが、次のような欠点があつた。 From the reference voltage V, so that a voltage corresponding to r in equation (4) is applied to the negative input of the operational amplifier 5,
I balanced the cable resistance r by adjusting VR, but the following drawbacks occurred.
(イ) 測定する条件により、ケーブルの長さや太さ
が異なりケーブル抵抗が変化するので、その度
にVRを調整する必要がある。(b) The cable length and thickness vary depending on the measurement conditions, and the cable resistance changes, so it is necessary to adjust VR each time.
(ロ) 一度VRを調整した後でも、温度によりケー
ブル抵抗が変化すると、その変化分だけ誤差が
生じる。(b) Even after adjusting the VR, if the cable resistance changes due to temperature, an error will occur by the amount of that change.
(ハ) 多点切換器を介して多点測定する場合、個々
の測定点のケーブルの長さが異なると、測定点
数と同数のVRを用意しなければならない。(c) When performing multi-point measurements via a multi-point switch, if the cable lengths of the individual measurement points are different, it is necessary to prepare the same number of VRs as the number of measurement points.
次に(イ)〜(ハ)の欠点を除去するための自動演算補
償回路を内蔵した従来からある一例のブロツク図
を第３図に示す。 Next, FIG. 3 shows a block diagram of a conventional example incorporating an automatic compensating circuit for eliminating the drawbacks (a) to (c).
第３図は、測定装置１″の接続端子ａ，ｂ，ｃ
と電圧計３の間に演算増幅器６，７，８が接続さ
れる点が異なるだけで、他はすべて第１図と同様
の構成である。 Figure 3 shows connection terminals a, b, c of measuring device 1''.
The configuration is the same as in FIG. 1 except that operational amplifiers 6, 7, and 8 are connected between the voltmeter 3 and the voltmeter 3.
演算増幅器６でe′＝（Ｒ＋ｒ）Ｉ、演算増幅器
７でe″＝ｒ・Ｉ成分の電圧をそれぞれ検出し、演
算増幅器８でe′−e″を演算してｅ＝Ｒ・Ｉの(1)式
と同じ出力電圧を電圧計３で測定し、その結果を
表示器４に表示する。 The operational amplifier 6 detects the voltage of e′=(R+r)I and the operational amplifier 7 detects the voltage of e″=r・I component, and the operational amplifier 8 calculates e′−e″ and calculates e=R・I ( Measure the same output voltage as in formula 1) with voltmeter 3, and display the result on display 4.
ところが接続端子ａ，ｂ，ｃと電圧計３の間に
演算増幅器６，７，８が挿入されるので、次のよ
うな欠点があつた。 However, since operational amplifiers 6, 7, and 8 were inserted between the connection terminals a, b, and c and the voltmeter 3, the following drawbacks occurred.
(ニ) 信号源インピーダンスとなるＲおよびｒの値
が、大きな値をとる測定の場合、e′，e″の２成
分電圧を検出する演算増幅器６，７の入力バイ
アス電流および入力インピーダンスの特性によ
つて発生する電位変化および感度変化の測定誤
差が、第１図および第２図の１成分電圧を検出
する電圧計３の特性と、演算増幅器６，７の特
性とが同じであれば、より大きく発生する。(d) In the case of measurements where the values of R and r, which are signal source impedances, are large values, the characteristics of the input bias current and input impedance of the operational amplifiers 6 and 7 that detect the two-component voltages e' and e'' If the characteristics of the voltmeter 3 that detects the one-component voltage in FIGS. 1 and 2 and the characteristics of the operational amplifiers 6 and 7 are the same, the measurement error of the potential change and sensitivity change that occurs will be reduced. Occurs greatly.
(ホ) 前記(ニ)項のＲおよびｒの測定条件の他に６，
７，８の３個の演算増幅器自体の零位変化およ
び感度変化による測定誤差が発生する。(e) In addition to the measurement conditions for R and r in item (d) above, 6.
Measurement errors occur due to zero level changes and sensitivity changes of the three operational amplifiers 7 and 8.
本発明は上記(イ)〜(ホ)の欠点に鑑みなされたもの
で、その目的は、各被測定体から抵抗体測定装置
までの距離やケーブルの太さが異なつても、また
温度によりケーブル抵抗が変化してもそのケーブ
ル抵抗の影響を受けることなく、測定点数がいか
に多くても構成が複雑化することがなく、被測定
体やケーブル抵抗の測定条件と演算増幅器の特性
との要因で発生する測定誤差がなく、さらに１対
のスイツチにより共通の回路素子を用いて定電流
回路と定電圧回路とを簡単に変換し得る安価な抵
抗体測定装置を提供することにある。 The present invention has been made in view of the above drawbacks (a) to (e), and its purpose is to provide cables that can be used even if the distance from each object to be measured to the resistance measuring device and the thickness of the cable are different, and also depending on the temperature. Even if the resistance changes, it will not be affected by the cable resistance, and no matter how many measurement points there are, the configuration will not become complicated. It is an object of the present invention to provide an inexpensive resistor measuring device that does not generate measurement errors and can easily convert between a constant current circuit and a constant voltage circuit using a common circuit element using a pair of switches.
本発明は、上記の目的を達成させるため、励振
電源の一方の出力端と他方の出力端に各基端が接
続された第１および第２のケーブルの各先端にそ
れぞれ被測定抵抗体の一端および他端を接続する
と共に、前記第１のケーブルの基端に電圧計の一
方の入力端を接続し、前記被測定抵抗体の前記他
端に前記第１および第２のケーブルと同等の第３
のケーブルを介して前記電圧計の他方の入力端を
接続して、前記励振電源により励振された前記被
測定抵抗体より出力される電圧に基づいて被測定
抵抗体の抵抗値を測定する３線式抵抗体測定装置
であつて、前記第１のケーブルの基端に出力端が
接続された一つの演算増幅器と、この演算増幅器
の一方の入力端に基準電圧を印加する基準電圧源
と、定電流を生成するための基準抵抗と、前記一
方の出力端と前記他方の出力端から定電流または
定電圧を選択的に出力すべく定電流回路または定
電圧回路を選択的に形成させる１対のスイツチと
からなる励振電源と、
前記第１および第３のケーブルを介して前記被
測定抵抗体の前記一端および他端に接続される電
圧計と、
前記１対のスイツチに連動し前記電圧計の測定
値を一時記憶する複数のメモリと、
このメモリから測定値を受け前記第１、第２お
よび第３のケーブルの内部抵抗に無関係な所定の
演算式により前記被測定抵抗体の抵抗値を算出す
る演算器と、
この演算器による演算結果を表示する表示器
と、
前記スイツチ、電圧計、メモリ、演算器および
表示器の動作順序を制御する制御器とを具備して
なり、前記制御器により、前記スイツチが定電流
回路および定電圧回路を形成し、前記励振電源が
前記被測定抵抗体を定電流励振して前記電圧計に
より得られた第１の測定値と定電圧励振して前記
電圧計により得られた第２の測定値とを、各々前
記メモリに一時記憶し、このメモリに記憶された
前記第１および第２の測定値を前記演算器で受
け、前記所定の演算式に基づく演算を実行し、前
記第１、第２および第３のケーブルの内部抵抗の
影響を受けない被測定抵抗体の抵抗値に対応する
測定値を前記表示器に表示させるように構成した
ことを特徴とするものである。 In order to achieve the above object, the present invention provides one end of a resistor to be measured at each tip of a first and second cable whose base ends are connected to one output end and the other output end of an excitation power source. and the other end of the first cable, one input end of a voltmeter is connected to the base end of the first cable, and a second cable equivalent to the first and second cables is connected to the other end of the resistor to be measured. 3
The other input end of the voltmeter is connected to the other input end of the voltmeter via a cable, and the resistance value of the resistor to be measured is measured based on the voltage output from the resistor to be measured excited by the excitation power source. A resistor measuring device comprising: an operational amplifier whose output end is connected to the proximal end of the first cable; a reference voltage source that applies a reference voltage to one input end of the operational amplifier; a reference resistor for generating a current; and a pair of resistors for selectively forming a constant current circuit or a constant voltage circuit to selectively output a constant current or a constant voltage from the one output terminal and the other output terminal. an excitation power source consisting of a switch; a voltmeter connected to the one end and the other end of the resistor to be measured via the first and third cables; a plurality of memories for temporarily storing measured values; and a resistance value of the resistor to be measured is calculated based on a predetermined calculation formula unrelated to the internal resistances of the first, second, and third cables upon receiving the measured values from the memories. a display unit that displays the calculation results of the calculation unit; and a controller that controls the operating order of the switch, voltmeter, memory, calculation unit, and display unit; , the switch forms a constant current circuit and a constant voltage circuit, and the excitation power source excites the resistor to be measured with a constant current to obtain a first measurement value obtained by the voltmeter and constant voltage excitation to obtain the voltage. the second measured values obtained by the meter are temporarily stored in the memory, the first and second measured values stored in the memory are received by the arithmetic unit, and the calculation is performed based on the predetermined arithmetic expression. It is characterized by being configured to execute calculations and display on the display a measured value corresponding to the resistance value of the resistor to be measured which is not affected by the internal resistance of the first, second and third cables. That is.
以下図面により本発明を詳細に説明する。 The present invention will be explained in detail below with reference to the drawings.
第４図は本発明による一実施例のブロツク図で
あつて、本発明による３線式抵抗体測定装置１
は電圧計３と表示器４の間にメモリ９と演算器１
０が接続されている点と、励振電源１１が演算増
幅器で構成されたドライバ回路１２、基準電圧
Ｅ、基準抵抗R0およびドライバ回路１２を定電
流・定電圧励振に切り換えるためのスイツチS1，
S2で構成されている点と、前記スイツチS1，S2、
電圧計３、メモリ９、演算器１０、表示器４を制
御する制御器１３で構成されている点が異なるの
みで、ほかは第１図と同様である。 FIG. 4 is a block diagram of an embodiment of the present invention, and shows a three-wire resistor measuring device 1 according to the present invention.
is the memory 9 and the calculator 1 between the voltmeter 3 and the display 4.
0 is connected, the excitation power supply 11 is connected to a driver circuit 12 composed of an operational amplifier, a reference voltage E, a reference resistor R 0 and a switch S 1 for switching the driver circuit 12 to constant current/constant voltage excitation.
S 2 and the switches S 1 , S 2 ,
The only difference is that it is comprised of a voltmeter 3, a memory 9, an arithmetic unit 10, and a controller 13 that controls the display 4, and the rest is the same as in FIG.
はじめにスイツチS1，S2を開にすると、ドライ
バ回路１２はＩ＝Ｅ／R0なる定電流値でＲを励
振する。その時の電圧計３の入力電圧をe2とする
と、(5)式のようになる。 When the switches S 1 and S 2 are first opened, the driver circuit 12 excites R with a constant current value of I=E/R 0 . If the input voltage of the voltmeter 3 at that time is e2 , then the equation (5) is obtained.
e2＝（Ｒ＋2r＋R0）Ｉ −（ｒ＋R0）Ｉ＝RI＋rI ……(5) (5)式よりＲを求めると(6)式のようになる。 e 2 =(R+2r+R 0 )I −(r+R 0 )I=RI+rI (5) When R is determined from equation (5), equation (6) is obtained.
Ｒ＝e2／Ｉ−ｒ ……(6)
次にスイツチS1，S2を閉にすると、ドライバ回
路１２はＥなる定電圧値でＲを励振する。その時
の電圧計３の入力電圧をe3とすると(7)式のように
なる。 R=e 2 /I−r (6) Next, when the switches S 1 and S 2 are closed, the driver circuit 12 excites R with a constant voltage value E. If the input voltage of the voltmeter 3 at that time is e3 , then the equation (7) is obtained.
e3＝Ｅ−（Ｅ／Ｒ＋2r）ｒ＝（Ｒ＋ｒ／Ｒ＋2r）Ｅ…
…(7)
(7)式よりＲを求めると(8)式のようになる。 e 3 =E-(E/R+2r)r=(R+r/R+2r)E...
...(7) Calculating R from equation (7) gives equation (8).
Ｒ＝（2e3−Ｅ／Ｅ−e3）ｒ ……(8)
(6)，(8)はいずれもケーブル抵抗ｒの影響を受け
ているが、(6)，(8)式よりＲ，ｒの１次元連立方程
式として、Ｒを求めるとケーブル抵抗ｒに無関係
な(9)式を得ることができる。 R=(2e 3 −E/E−e 3 )r ...(8) Both (6) and (8) are affected by the cable resistance r, but from equations (6) and (8), R , r as a one-dimensional simultaneous equation, equation (9) can be obtained that is independent of the cable resistance r.
Ｒ＝e2／Ｉ（２−Ｅ／e3） ……(9)
従つてケーブル抵抗ｒに関係なく、スイツチ
S1，R2を開にして被測定体Ｒを定電流励振した
時の電圧計３の入力電圧e2と、S1，S2を閉にして
定電圧励振した時の入力電圧e3とを電圧計３で測
定し、これらe2，e3を２個のメモリ９に一時記憶
し、(9)式に従つた演算を演算器１０で行い、その
結果を表示器４で表示するように制御器１３で動
作順序を制御することによつて、ケーブル抵抗ｒ
の影響を受けない真の抵抗Ｒを測定することがで
きる。 R=e 2 /I (2-E/e 3 ) ...(9) Therefore, regardless of the cable resistance r, the switch
The input voltage e 2 of the voltmeter 3 when S 1 and R 2 are opened and the measured object R is excited with constant current, and the input voltage e 3 when S 1 and S 2 are closed and constant voltage excitation is applied. is measured with a voltmeter 3, these e 2 and e 3 are temporarily stored in two memories 9, calculations according to equation (9) are performed in a calculator 10, and the results are displayed on a display 4. By controlling the operation sequence with the controller 13, the cable resistance r
It is possible to measure the true resistance R that is not affected by
以上説明したように、本発明の抵抗体測定装置
には、次の利点がある。 As explained above, the resistor measuring device of the present invention has the following advantages.
（） 測定条件、温度変化によるケーブル抵抗
の影響がない。() There is no effect of cable resistance due to measurement conditions or temperature changes.
（） 多点切換器を介して多点測定する場合、
測定点数が増加しても２個のメモリですむ。() When performing multi-point measurements via a multi-point switch,
Even if the number of measurement points increases, only two memories are required.
（） 被測定体と電圧計の間に演算増幅器が存
在しないので、被測定体やケーブル抵抗の測定
条件と演算増幅器の特性との要因で発生する測
定誤差がないこと、また電圧計をデイジタル電
圧計、メモリをデイジタルメモリ、演算器をデ
イジタル演算器、表示器をデイジタル表示器で
簡単に構成できるので、第３図の３個の演算増
幅器自体で発生する零位・感度変化の測定誤差
を排除することができる。() Since there is no operational amplifier between the device under test and the voltmeter, there is no measurement error caused by the measurement conditions of the device under test or cable resistance and the characteristics of the operational amplifier, and the voltmeter is connected to the digital voltage. The meter and memory can be easily configured with digital memory, the arithmetic unit with a digital arithmetic unit, and the display with a digital display, eliminating measurement errors due to zero level and sensitivity changes that occur in the three operational amplifiers themselves shown in Figure 3. can do.
（） 本発明によれば、スイツチ２個で簡単に
定電流回路を定電圧回路に変換することができ
るので、個々に定電流回路と定電圧回路の両方
を同時に内蔵する必要がない。() According to the present invention, a constant current circuit can be easily converted into a constant voltage circuit with two switches, so there is no need to individually incorporate both a constant current circuit and a constant voltage circuit at the same time.
さらに本発明の構成によると、定電流のみなら
ず定電圧励振できる励振電源と、１成分の汎用電
圧測定の入力形態をもつ電圧計で構成されてお
り、かつ制御器、メモリ、演算器が簡単にマイク
ロコンピユータに置き換えることができ、これら
をマイクロコンピユータで構成すれば、動作順序
の制御や演算処理のプログラムのみを変更するこ
とにより、抵抗体測定分野のほかに、ホイートス
トンブリツジ測定分野の装置にも応用できる。 Furthermore, according to the configuration of the present invention, it is composed of an excitation power source that can excite not only constant current but also constant voltage, and a voltmeter that has an input form for one-component general-purpose voltage measurement, and the controller, memory, and computing unit are simple. By configuring these with microcomputers, by changing only the operation order control and arithmetic processing programs, it can be used not only in the resistor measurement field but also in the Wheatstone bridge measurement field. can also be applied.
第１図はケーブル抵抗補償のない３線式抵抗体
測定装置の一例を示すブロツク図、第２図および
第３図は従来からあるケーブル抵抗補償のある３
線式抵抗体測定装置の一例を示すブロツク図、第
４図は本発明による３線式抵抗体測定装置の一例
を示すブロツク図である。
１，１′，１″，１…３線式抵抗体測定装置、
２…定電流回路、３…電圧計、４…表示器、５，
６，７，８…演算増幅器、９…メモリ、１０…演
算器、１１…定電流回路と定電圧回路を内蔵する
励振電源、１２…ドライバ回路、１３…制御器、
Ｒ…被測定体、ｒ…ケーブル抵抗、ａ，ｂ，ｃ…
接続端子、ｅ…電圧計の入力電圧、e′，e″…演算
増幅器６，７の入力電圧、S1，S2…スイツチ、
VR…可変抵抗器、Ｉ…定電流回路の定電流値、
Ｅ…定電圧回路の定電圧値、Ｖ…基準電圧、R0
…基準抵抗。
Fig. 1 is a block diagram showing an example of a 3-wire resistance measuring device without cable resistance compensation, and Figs.
FIG. 4 is a block diagram showing an example of a three-wire resistor measuring device according to the present invention. 1, 1', 1'', 1... 3-wire resistor measuring device,
2... constant current circuit, 3... voltmeter, 4... indicator, 5,
6, 7, 8... operational amplifier, 9... memory, 10... arithmetic unit, 11... excitation power supply with built-in constant current circuit and constant voltage circuit, 12... driver circuit, 13... controller,
R...Object to be measured, r...Cable resistance, a, b, c...
Connection terminal, e...Input voltage of voltmeter, e', e''...Input voltage of operational amplifiers 6, 7, S1 , S2 ...Switch,
VR...variable resistor, I...constant current value of constant current circuit,
E... Constant voltage value of constant voltage circuit, V... Reference voltage, R 0
...Reference resistance.
Claims (1)
基端が接続された第１および第２のケーブルの各
先端にそれぞれ被測定抵抗体の一端および他端を
接続すると共に、前記第１のケーブルの基端に電
圧計の一方の入力端を接続し、前記被測定抵抗体
の前記他端に前記第１および第２のケーブルと同
等の第３のケーブルを介して前記電圧計の他方の
入力端を接続して、前記励振電源により励振され
た前記被測定抵抗体より出力される電圧に基づい
て被測定抵抗体の抵抗値を測定する３線式抵抗体
測定値であつて、前記第１のケーブルの基端に出
力端が接続された一つの演算増幅器と、この演算
増幅器の一方の入力端に基準電圧を印加する基準
電圧源と、定電流を生成するための基準抵抗と、
前記一方の出力端と前記他方の出力端から定電流
または定電圧を選択的に出力すべく定電流回路ま
たは定電圧回路を選択的に形成させる１対のスイ
ツチとからなる励振電源と、 前記第１および第３のケーブルを介して前記被
測定抵抗体の前記一端および他端に接続される電
圧計と、 前記１対のスイツチに連動し前記電圧計の測定
値を一時記憶する複数のメモリと、 このメモリからの測定値を受け前記第１、第２
および第３のケーブルの内部抵抗に無関係な所定
の演算式により前記被測定抵抗体の抵抗値を算出
する演算器と、 この演算器による演算結果を表示する表示器
と、 前記スイツチ、電圧計、メモリ、演算器および
表示器の動作順序を制御する制御器と を具備してなり、前記制御器により、前記スイツ
チが定電流回路および定電圧回路を選択的に形成
し、前記励振電源が前記被測定抵抗体を定電流励
振して前記電圧計により得られた第１の測定値と
定電圧励振して前記電圧計により得られた第２の
測定値とを、各々前記メモリに一時記憶し、この
メモリに記憶された前記第１および第２の測定値
を前記演算器で受け、前記所定の演算式に基づく
演算を実行し、前記第１、第２および第３のケー
ブルの内部抵抗の影響を受けない被測定抵抗体の
抵抗値に対応する測定値を前記表示器に表示させ
ることを特徴とする抵抗体測定装置。[Claims] 1. One end and the other end of the resistor to be measured are connected to the respective tips of the first and second cables whose base ends are connected to one output end and the other output end of the excitation power source, respectively. At the same time, one input end of a voltmeter is connected to the base end of the first cable, and a third cable equivalent to the first and second cables is connected to the other end of the resistor to be measured. 3-wire resistor measurement, in which the other input end of the voltmeter is connected to the voltmeter, and the resistance value of the resistor to be measured is measured based on the voltage output from the resistor to be measured excited by the excitation power source. an operational amplifier whose output end is connected to the proximal end of the first cable; a reference voltage source that applies a reference voltage to one input end of the operational amplifier; and a reference voltage source that generates a constant current. and the reference resistance for
an excitation power source comprising a pair of switches that selectively form a constant current circuit or a constant voltage circuit to selectively output a constant current or constant voltage from the one output terminal and the other output terminal; a voltmeter connected to the one end and the other end of the resistor to be measured via first and third cables; and a plurality of memories that are linked to the pair of switches and temporarily store the measured values of the voltmeter. , receiving the measured values from this memory, the first and second
and a computing unit that calculates the resistance value of the resistor to be measured using a predetermined computing formula that is unrelated to the internal resistance of the third cable; a display that displays the calculation result of the computing unit; the switch, the voltmeter, a controller for controlling the order of operation of a memory, an arithmetic unit, and a display; the controller causes the switch to selectively form a constant current circuit and a constant voltage circuit; Temporarily storing in the memory a first measurement value obtained by the voltmeter by constant current excitation of the measuring resistor and a second measurement value obtained by the voltmeter by constant voltage excitation, respectively; The first and second measured values stored in this memory are received by the arithmetic unit, and an arithmetic operation based on the predetermined arithmetic expression is performed to determine the influence of the internal resistance of the first, second and third cables. A resistor measuring device characterized in that the display device displays a measured value corresponding to a resistance value of a resistor to be measured which is not subjected to
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP12397080A JPS5748667A (en) | 1980-09-09 | 1980-09-09 | Resistor measuring device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP12397080A JPS5748667A (en) | 1980-09-09 | 1980-09-09 | Resistor measuring device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5748667A JPS5748667A (en) | 1982-03-20 |
| JPS6314784B2 true JPS6314784B2 (en) | 1988-04-01 |
Family
ID=14873814
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP12397080A Granted JPS5748667A (en) | 1980-09-09 | 1980-09-09 | Resistor measuring device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5748667A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02144988U (en) * | 1989-05-10 | 1990-12-10 |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61193078A (en) * | 1985-02-21 | 1986-08-27 | Niigata Eng Co Ltd | Measuring instrument for pressure or the like |
| JPS62212575A (en) * | 1986-03-14 | 1987-09-18 | Sakata Denki Kk | System for measuring resistance ratio of variable resistor equipped with cable resistance correcting function |
| JP4735088B2 (en) * | 2005-07-08 | 2011-07-27 | 株式会社安川電機 | Servo amplifier module |
| TWI622780B (en) * | 2016-11-28 | 2018-05-01 | Dhc Specialty Corp | Asymmetric battery detection device |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS54137378A (en) * | 1978-04-17 | 1979-10-25 | Sharp Corp | Resistance meter |
-
1980
- 1980-09-09 JP JP12397080A patent/JPS5748667A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS54137378A (en) * | 1978-04-17 | 1979-10-25 | Sharp Corp | Resistance meter |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02144988U (en) * | 1989-05-10 | 1990-12-10 |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5748667A (en) | 1982-03-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US3535637A (en) | Calibration of electrical measuring transducer devices | |
| US3847017A (en) | Strain measuring system | |
| US4060715A (en) | Linearized bridge circuitry | |
| US3284709A (en) | Precision voltmeter using selectable series connected, digitally related resistors which are calibrated to read the value of input signal | |
| US4823087A (en) | Salimeter | |
| EP0496147A1 (en) | Method of precise measurement of small resistance values | |
| US3319155A (en) | Electrical calibration device for strain gage bridges | |
| US8872530B2 (en) | Method for correcting the voltage measured across the terminals of a sensor | |
| JPS6314784B2 (en) | ||
| US3068410A (en) | Expanded scale electrical measuring system having high temperature stability | |
| JPH0240567A (en) | Measuring apparatus of current with automatic calibration function | |
| US3453536A (en) | Common power supply resistance bridge system providing excitation,individual bridge sensor resistance,and signal output terminals all referenced to a common potential | |
| JPH052185B2 (en) | ||
| JP3716308B2 (en) | High resistance measuring method and high resistance measuring apparatus | |
| US4156181A (en) | Ratio circuit | |
| JP2544130B2 (en) | Temperature measurement circuit | |
| US20210156896A1 (en) | Circuit arrangement and method for determining a resistance change and methods for determining lead resistances | |
| US2866948A (en) | Test circuit for interconnected components | |
| US3495169A (en) | Modified kelvin bridge with yoke circuit resistance for residual resistance compensation | |
| US3421082A (en) | Rebalancing voltmeter having voltage responsive error sensing means and means to buck out current drawn by an input impedance | |
| US3060743A (en) | Linearized measuring device | |
| JP2000249507A (en) | Strain measuring system | |
| JP3619816B2 (en) | Strain gauge pseudo-resistor and strain calibrator | |
| SU705349A1 (en) | Resistance meter | |
| JPH02147901A (en) | Strain gauge type converter |