CN2215112Y - Automatic compensation system of resistance sensor lead wire - Google Patents
Automatic compensation system of resistance sensor lead wire Download PDFInfo
- Publication number
- CN2215112Y CN2215112Y CN 95203244 CN95203244U CN2215112Y CN 2215112 Y CN2215112 Y CN 2215112Y CN 95203244 CN95203244 CN 95203244 CN 95203244 U CN95203244 U CN 95203244U CN 2215112 Y CN2215112 Y CN 2215112Y
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- China
- Prior art keywords
- resistance
- utility
- lead
- model
- resistance sensor
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- 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 - Fee Related
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Abstract
The utility model relates to a special accessory of an industrial automated instrument, particularly an automatic compensation device of a resistance type sensor lead wire. The utility model has the technical proposal that the utility model comprises two precise constant-current sources I1, I2; the two precise constant-current sources are respectively connected with two lead wires from a resistance type sensor Rx to a secondary display instrument Y; the resistance values of the three lead wires of the resistance type sensor are completely equal. The utility model has the advantage of reasonable structure and can completely eliminate the influence of the lead wire resistance on measuring results. The length of the lead wires from the sensor to the secondary instrument can be arbitrary, which is convenient for use.
Description
The utility model relates to a kind of industrial automation instrument special accessories, particularly resistance sensor lead-in wire autocompensation installation.
At present, connect in the industrial instrument of resistance sensor, resistance sensor to secondary Displaying Meter generally adopts three-wire system to connect, the resistance value wire length of instrument (embody) of lead-in wire is defined as r＜10 ohm, r＜15 ohm etc. usually, or r=5 ohm, 10 ohm, 15 ohm etc., the previous case shows that lead resistance must be controlled in the setting; Latter event shows that lead resistance must adjust to setting; Otherwise will increase measuring error, the precision that the instrument indicated value can not be met the demands.This device uses very loaded down with trivial details, needs the artificial lead resistance of adjusting, and easily produces error.
The utility model purpose be to overcome above-mentioned shortcoming of the prior art and provide a kind of rational in infrastructure, eliminate the resistance sensor lead-in wire autocompensation installation of lead resistance to the measuring error influence.
The purpose of this utility model is achieved by the following technical solution: comprise two identical precision constant current sources in the composition of the present utility model, these two precision constant current sources are connected to resistance sensor to two lead-in wires of secondary Displaying Meter, and the resistance value of three lead-in wires of resistance sensor is equal fully.
If the resistance of three lead-in wires is r1, r2, r3.Then:
r1＝r2＝r3＝r －－－－－（1）
Resistance sensor resistance R x is by precision constant current source I1, I2 power supply, and signal amplification circuit adopts integrated operational amplifier, and input impedance is the M ohm level, input bias current＜1 microampere, and input mode is the input of difference symmetry; And sensor electrical resistance working range is usually between 10 ohm to 1000 ohm; Get I1=I2, the electric current of establishing two precision constant current source flow direction sensors is I3, I4, and the electric current that ground lead flows through is I5, therefore has:
I3＝I4 －－－－－－－－－（2）
I5＝I3＋I4 －－－－－－（3）
Like this, the input voltage signal of signal amplification circuit acquisition is
Ui＝I3×r1＋I3×Rx＋I5×r3－I4×r2－I5×r3
Formula (1), (2), (3) substitution are got:
Ui＝I×Rx
Like this, Ui is only relevant with I and Rx, and is irrelevant with lead resistance.
The utlity model has rational in infrastructure, eliminate the characteristics such as influence of lead resistance fully to measurement result, can make sensor to the wire length of secondary instrument for arbitrarily, the convenient use.
Fig. 1 is the utility model schematic diagram.
Fig. 2 is the utility model example structure synoptic diagram.
Below with reference to accompanying drawings, further specify the utility model by embodiment.
In an embodiment, comprise two identical 4DH series precision constant current source I1, I2 in the composition of the present utility model, I1 forms the loop by V+, r1, Rx, r3, and I2 forms the loop by V+, r2, Rx, R3.The signal voltage that forms on Rx is introduced secondary Displaying Meter Y by r1, r2.Thoroughly eliminated the influence of lead resistance to measurement result.
Claims (1)
1, a kind of resistance sensor lead-in wire autocompensation installation, be arranged between resistance sensor Rx and the secondary Displaying Meter Y, comprise two precision constant current source I1, I2 in it is characterized in that forming, these two precision constant current sources are connected to resistance sensor to two lead-in wires of secondary Displaying Meter, and the resistance value of three lead-in wires of resistance sensor is equal fully.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 95203244 CN2215112Y (en) | 1995-02-24 | 1995-02-24 | Automatic compensation system of resistance sensor lead wire |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 95203244 CN2215112Y (en) | 1995-02-24 | 1995-02-24 | Automatic compensation system of resistance sensor lead wire |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN2215112Y true CN2215112Y (en) | 1995-12-13 |
Family
ID=33856146
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 95203244 Expired - Fee Related CN2215112Y (en) | 1995-02-24 | 1995-02-24 | Automatic compensation system of resistance sensor lead wire |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN2215112Y (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104614589A (en) * | 2015-01-19 | 2015-05-13 | 浙江中控自动化仪表有限公司 | Lead-resistance-removed resistance signal source and resistance measuring circuit thereof |
| CN109870487A (en) * | 2019-02-18 | 2019-06-11 | 中国石油天然气集团有限公司 | A kind of calibrating conductor resistance compensation method of conductivity sensor and device and system |
-
1995
- 1995-02-24 CN CN 95203244 patent/CN2215112Y/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104614589A (en) * | 2015-01-19 | 2015-05-13 | 浙江中控自动化仪表有限公司 | Lead-resistance-removed resistance signal source and resistance measuring circuit thereof |
| CN104614589B (en) * | 2015-01-19 | 2017-07-28 | 浙江中控自动化仪表有限公司 | Resistance signal source and its resistance measuring circuit that a kind of lead resistance is eliminated |
| CN109870487A (en) * | 2019-02-18 | 2019-06-11 | 中国石油天然气集团有限公司 | A kind of calibrating conductor resistance compensation method of conductivity sensor and device and system |
| CN109870487B (en) * | 2019-02-18 | 2021-06-22 | 中国石油天然气集团有限公司 | Method, device and system for compensating resistance of conductivity sensor verification lead |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C19 | Lapse of patent right due to non-payment of the annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |