JPH023443B2 - - Google Patents
Info
- Publication number
- JPH023443B2 JPH023443B2 JP4607982A JP4607982A JPH023443B2 JP H023443 B2 JPH023443 B2 JP H023443B2 JP 4607982 A JP4607982 A JP 4607982A JP 4607982 A JP4607982 A JP 4607982A JP H023443 B2 JPH023443 B2 JP H023443B2
- Authority
- JP
- Japan
- Prior art keywords
- capacitance
- displacement meter
- switch
- ground electrode
- response characteristics
- 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
- 238000006073 displacement reaction Methods 0.000 claims description 21
- 238000005259 measurement Methods 0.000 claims description 20
- 239000002184 metal Substances 0.000 claims description 12
- 239000000523 sample Substances 0.000 claims description 12
- 238000000034 method Methods 0.000 claims description 4
- 238000010998 test method Methods 0.000 claims description 3
- 238000012360 testing method Methods 0.000 description 6
- 238000010586 diagram Methods 0.000 description 4
- 239000003990 capacitor Substances 0.000 description 3
- 230000035945 sensitivity Effects 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B7/00—Measuring arrangements characterised by the use of electric or magnetic techniques
- G01B7/14—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring distance or clearance between spaced objects or spaced apertures
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Measurement Of Length, Angles, Or The Like Using Electric Or Magnetic Means (AREA)
Description
【発明の詳細な説明】
本発明は間隔の測定、被測定物の厚さの測定等
に利用される静電容量型変位計の応答特性の試験
方法に関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for testing the response characteristics of a capacitive displacement meter used for measuring distances, measuring the thickness of objects to be measured, and the like.
静電容量型変位計の測定対象物は主として機械
であるため、機械の瞬時の変位に対する応答特性
が性能上重視されているが、従来はこの応答特性
の適当な試験方法がなかつた。従つて、変位計内
部の増幅器あるいはフイルタの周波数特性を計算
式で求めることによつて応答特性を決定すること
があつたが、実際の反答特性と計算による応答特
性との間に誤差が生じることが多かつた。また、
最近では変位計の感度が向上し、検出する静電容
量の値も0.0001pF程度の非常に微小な値であるた
め、外部の測定装置による浮遊容量による影響も
大きく、変位計の応答特性を直視することは困難
であつた。 Since the object to be measured by a capacitive displacement meter is mainly a machine, the response characteristics to the instantaneous displacement of the machine are important in terms of performance, but conventionally there has been no suitable test method for this response characteristic. Therefore, the response characteristics have sometimes been determined by calculating the frequency characteristics of the amplifier or filter inside the displacement meter using a calculation formula, but an error occurs between the actual response characteristics and the calculated response characteristics. There were many things. Also,
Recently, the sensitivity of displacement meters has improved, and the detected capacitance value is extremely small, around 0.0001pF, so the influence of stray capacitance from external measuring devices is large, and the response characteristics of displacement meters must be directly examined. It was difficult to do so.
そこで、本発明の目的は、容易且つ正確な静電
容量型変位計の応答特性試験方法を提供すること
にある。 SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an easy and accurate method for testing the response characteristics of a capacitive displacement meter.
上記目的を達成するための本発明は、静電容量
型変位計の測定プローブと接地電極との間に金属
板を配置し且つ前記金属板を前記接地電極との間
にスイツチを接続し、前記スイツチの開閉に対応
した前記静電容量型変位計の測定回路の出力の変
化に基づいて前記静電容量型変位計の応答特性を
測定することを特徴とする試験方法に係わるもの
である。 In order to achieve the above object, the present invention disposes a metal plate between a measurement probe of a capacitance type displacement meter and a ground electrode, and connects a switch between the metal plate and the ground electrode. The present invention relates to a test method characterized in that the response characteristics of the capacitive displacement meter are measured based on changes in the output of a measurement circuit of the capacitive displacement meter corresponding to opening and closing of a switch.
上記発明によれば、金属板とスイツチを配し、
スイツチを開閉するのみで、応答特性を知ること
が出来る。従つて、応答特性の測定を安価な装置
で容易に行うことが可能になる。また外部浮遊容
量の影響を受けずに測定することが可能であるの
で、正確且つ安定的に応答特性を知ることが可能
になる。 According to the above invention, the metal plate and the switch are arranged,
You can know the response characteristics just by opening and closing the switch. Therefore, it becomes possible to easily measure the response characteristics using an inexpensive device. Furthermore, since it is possible to measure without being affected by external stray capacitance, it is possible to accurately and stably know the response characteristics.
次に、図面を参照して本発明の実施例について
述べる。 Next, embodiments of the present invention will be described with reference to the drawings.
第１図は静電容量型変位計の応答特性を測定し
ている状態を示すものである。この図に於いて、
１は測定プローブ即ち静電容量測定用の電極であ
り、その測定面が接地電極２との間に一定間隔を
有して対向配置されている。３は静電容量型変位
計の測定回路であり、プローブ１と接地電極２と
の間の静電容量に対応した出力を発生する回路で
ある。４は応答特性測定用金属板であり、測定プ
ローブ１と接地電極２との間に配されている。５
は応答特性測定用スイツチであり、金属板４を接
地電極２に選択的に接続するものである。６はオ
シロスコープであり、測定回路３から出力される
静電容量の変化に対応して変化する出力電圧の波
形を測定するものである。 FIG. 1 shows a state in which the response characteristics of a capacitive displacement meter are being measured. In this diagram,
Reference numeral 1 denotes a measurement probe, that is, an electrode for measuring capacitance, and its measurement surface is placed opposite to a ground electrode 2 with a constant distance therebetween. 3 is a measurement circuit of a capacitance type displacement meter, which is a circuit that generates an output corresponding to the capacitance between the probe 1 and the ground electrode 2. Reference numeral 4 denotes a metal plate for measuring response characteristics, which is arranged between the measurement probe 1 and the ground electrode 2. 5
is a switch for measuring response characteristics, which selectively connects the metal plate 4 to the ground electrode 2. Reference numeral 6 denotes an oscilloscope, which measures the waveform of the output voltage that changes in response to changes in capacitance output from the measurement circuit 3.
第１図の測定回路３は、例えば、第２図に示す
如く測定プローブ１と接地電極２との間のコンデ
ンサCXと共にブリツジ回路を構成するコンデン
サ７，８，９、高周波発振器１０、整流回路１
１、及び増幅器１２から成り、コンデンサCXの
容量の変動分に比例した出力電圧を発生する静電
容量−電圧変換回路である。 The measurement circuit 3 in FIG. 1 includes, for example, capacitors 7, 8, 9, a high-frequency oscillator 10, and a rectifier circuit that constitute a bridge circuit together with a capacitor CX between the measurement probe 1 and the ground electrode 2, as shown in FIG. 1
1 and an amplifier 12, this is a capacitance-to-voltage conversion circuit that generates an output voltage proportional to the variation in the capacitance of the capacitor C.
第１図に示すように試験装置を構成すれば、測
定プローブ１と金属板４との間に静電容量C1、
金属板４と接地電極２との間に静電容量C2が得
られ、更にスイツチ５の両端間に浮遊容量C3が
得られる。ところで、スイツチ５が閉成状態の場
合には金属板４と接地電極２とは短絡されるため
に、測定プローブ１の接地電極２に対する静電容
量C0は、
C0＝C1 ……(1)
となり、スイツチ(5)が開成状態の場合には、第１
の容量C1、C2、C3の全部が生じるために、測定
プローブ１と接地電極２との間の静電容量Ｃは、
Ｃ＝C1（C2＋C3）／C1＋C2＋C3 ……(2)
となる。従つて、スイツチ５の開閉による測定プ
ローブ１に於ける静電容量の変化分△Ｃは次式で
表わされる。 If the test apparatus is configured as shown in FIG. 1, a capacitance C 1 between the measurement probe 1 and the metal plate 4,
A capacitance C 2 is obtained between the metal plate 4 and the ground electrode 2, and a stray capacitance C 3 is obtained between both ends of the switch 5. By the way, when the switch 5 is in the closed state, the metal plate 4 and the ground electrode 2 are short-circuited, so the capacitance C 0 of the measurement probe 1 with respect to the ground electrode 2 is C 0 =C 1 ...( 1), and when switch (5) is open, the first
Because all of the capacitances C 1 , C 2 and C 3 occur, the capacitance C between the measuring probe 1 and the ground electrode 2 is: C=C 1 (C 2 +C 3 )/C 1 +C 2 +C 3 ...(2) becomes. Therefore, the change in capacitance ΔC in the measurement probe 1 due to opening and closing of the switch 5 is expressed by the following equation.
△Ｃ＝C1−C1（C2＋C3）／C1＋C2＋C3＝C1C1／C1＋C2
＋C3……(3)
金属板４を接地電極２より十分に離らかして配
置すれば、C2≪C3、C2≪C1となり、(3)式に基づ
いて次式が得られる。 △C= C1 - C1 ( C2 + C3 )/ C1 + C2 + C3 = C1C1 / C1 + C2
+C 3 ...(3) If the metal plate 4 is placed sufficiently apart from the ground electrode 2, C 2 << C 3 , C 2 <<C 1 , and the following equation can be obtained based on equation (3). It will be done.
△Ｃ＝C1 2／C1＋C3 ……(4)
スイツチ５の開又は閉は静電容量型変位計の応
答時間に対して十分無視し得る短時間内で行うこ
とが可能であるため、(4)式の△Ｃは立上り又は立
下り時間を無視し得る理想的なステツプ状の静電
容量の変化であり、測定回路３の出力端子にはス
テツプ状の容量変化に対応した出力電圧が現わ
れ、これがオシロスコープ６に表示される。即
ち、測定プローブ１に於ける容量が第３図Ａに示
す如くステツプ状に変化し、測定回路３の出力電
圧は第３図Ｂに示すような応答特性を有して変化
する。従つて、第３図Ｂの波形をオシロスコープ
６で観測することにより、変位計の応答特性を直
ちに知ることができる。 △C=C 1 2 /C 1 +C 3 ...(4) Switch 5 can be opened or closed within a short time that can be sufficiently ignored compared to the response time of the capacitive displacement meter. , △C in equation (4) is an ideal step-like change in capacitance where the rise or fall time can be ignored, and the output terminal of the measurement circuit 3 has an output voltage corresponding to the step-like capacitance change. appears and is displayed on the oscilloscope 6. That is, the capacitance of the measuring probe 1 changes stepwise as shown in FIG. 3A, and the output voltage of the measuring circuit 3 changes with a response characteristic as shown in FIG. 3B. Therefore, by observing the waveform shown in FIG. 3B with the oscilloscope 6, the response characteristics of the displacement meter can be immediately known.
尚、第１図に於いて、C1＝0.1pF、C3＝1pF程
度にすることが可能であり、(4)式にこの値を代入
すると、
△Ｃ＝0.01／1.1≒0.009pF
となり、静電容量変位計の検出感度を0.0001pFと
すれば十分測定が可能である。 In addition, in Figure 1, it is possible to set C 1 = 0.1 pF and C 3 = approximately 1 pF, and by substituting these values into equation (4), △C = 0.01/1.1≒0.009 pF, If the detection sensitivity of the capacitance displacement meter is 0.0001pF, sufficient measurement is possible.
上述から明らかなように、本実施例の方法によ
れば、高感度の静電容量型変位計の応答特性を外
部浮遊容量の影響を受けずに正確に測定すること
が可能になる。また非接触状態で試験する回路構
成となるので、試験装置の構成を簡単且つ安価に
する事が出来る。また試験作業も容易になる。 As is clear from the above, according to the method of this embodiment, it is possible to accurately measure the response characteristics of a highly sensitive capacitive displacement meter without being affected by external stray capacitance. Furthermore, since the circuit configuration is tested in a non-contact state, the configuration of the testing device can be made simple and inexpensive. It also makes testing easier.
以上、本発明の実施例について述べたが、本発
明はこれに限定されるものではなく、更に変形可
能なものである。例えば、オシロスコープ６の代
りに別の表示装置又は記録装置又は指示計器を接
続してもよい。また、測定回路３を例えば実公昭
40−14455号公報に開示されているような構成と
してもよい。またスイツチ５をトランジスタスイ
ツチ等の電子スイツチとしてもよい。 Although the embodiments of the present invention have been described above, the present invention is not limited thereto and can be further modified. For example, instead of the oscilloscope 6, another display device, recording device, or indicating instrument may be connected. In addition, the measurement circuit 3 may be
A configuration as disclosed in Japanese Patent No. 40-14455 may be used. Further, the switch 5 may be an electronic switch such as a transistor switch.
第１図は本発明の実施例に係わる静電容量型変
位計の応答特性試験装置を示すブロツク図、第２
図は第１図の測定回路を詳しく示すブロツク図、
第３図は静電容量の変化と出力電圧の変化とを示
す波形図である。
尚図面に用いられている符号に於いて、１は測
定プローブ、２は接地電極、３は測定回路、４は
金属板、５はスイツチ、６はオシロスコープであ
る。
FIG. 1 is a block diagram showing a response characteristic testing device for a capacitive displacement meter according to an embodiment of the present invention, and FIG.
The figure is a block diagram showing the measurement circuit in Figure 1 in detail.
FIG. 3 is a waveform diagram showing changes in capacitance and changes in output voltage. In the symbols used in the drawings, 1 is a measurement probe, 2 is a ground electrode, 3 is a measurement circuit, 4 is a metal plate, 5 is a switch, and 6 is an oscilloscope.
Claims (1)
との間に金属板を配置し且つ前記金属板と前記接
地電極との間にスイツチを接続し、前記スイツチ
の開閉に対応した前記静電容量型変位計の測定回
路の出力の変化に基づいて変位計の応答特性を測
定することを特徴とする静電容量型変位計の試験
方法。1 A metal plate is arranged between the measurement probe of the capacitance type displacement meter and the ground electrode, and a switch is connected between the metal plate and the ground electrode, and the capacitance is adjusted according to the opening and closing of the switch. 1. A test method for a capacitive displacement meter, the method comprising measuring the response characteristics of a displacement meter based on changes in the output of a measurement circuit of the displacement meter.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4607982A JPS58162802A (en) | 1982-03-23 | 1982-03-23 | Method for testing electrostatic capacity type displacement meter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4607982A JPS58162802A (en) | 1982-03-23 | 1982-03-23 | Method for testing electrostatic capacity type displacement meter |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS58162802A JPS58162802A (en) | 1983-09-27 |
| JPH023443B2 true JPH023443B2 (en) | 1990-01-23 |
Family
ID=12736977
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4607982A Granted JPS58162802A (en) | 1982-03-23 | 1982-03-23 | Method for testing electrostatic capacity type displacement meter |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS58162802A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA1191261A (en) * | 1983-12-14 | 1985-07-30 | Francois Lalonde | Apparatus for dynamic and contactless measurement of small distances |
-
1982
- 1982-03-23 JP JP4607982A patent/JPS58162802A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS58162802A (en) | 1983-09-27 |
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