CN87209746U - Multifunctional digital thermometer with drift compensation - Google Patents
Multifunctional digital thermometer with drift compensation Download PDFInfo
- Publication number
- CN87209746U CN87209746U CN 87209746 CN87209746U CN87209746U CN 87209746 U CN87209746 U CN 87209746U CN 87209746 CN87209746 CN 87209746 CN 87209746 U CN87209746 U CN 87209746U CN 87209746 U CN87209746 U CN 87209746U
- Authority
- CN
- China
- Prior art keywords
- digital thermometer
- digital
- measuring resistance
- thermistor
- voltage
- 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.)
- Ceased
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Abstract
The utility model discloses a multifunctional digital thermometer with drift compensation belonging to the field of temperature measurement of thermistors. The multifunctional digital thermometer with drift compensation is composed of a four-wire thermistor linear detection circuit, a temperature measuring thermistor Rt, standard resistors (or potentiometers) ) R-[0] and R-[100], an amplifier (2), periodical sampling switches K-[1], K-[2] and K-[3], keeping capacitances Ct, Co and C-[100] and a non-internal reference-voltage digital voltage panel meter (3). The multifunctional digital thermometer with drift compensation has the advantages of high measuring precision, low cost and convenient use and automatically compensates the influence of the change of the environment temperature and the time drift, so the reference voltage can be used for the digital thermometer and various differential thermometers.
Description
Can the many of compensating circuit drift belong to the thermistor temp fields of measurement with digital thermometer.
General compensation by thermistor is made of testing circuit, amplifier, digital display circuit.These circuit are made up of tens components and parts.Nearly all components and parts all can be owing to variation of ambient temperature produces temperature drift, and in time can the generation time drift.These drifts all can influence the measured value of temperature, thereby have limited the high-acruracy survey of thermometer.
The compensation by thermistor of band microcomputer can carry out data processing then periodically to thermistor and the sampling of several measuring resistance at present, and output shows the measured temperature of having eliminated most components and parts drift influences.But still there is the influence of measuring resistance drift in it, and complex circuit, and cost is higher.
The present invention is on the basis of linearization testing circuit to the thermistor power supply, variation of ambient temperature and time drift are compensated automatically, make the drift of most components and parts no longer influence measured temperature, main error only is confined in the drift of two measuring resistance elements, thereby has improved the measuring accuracy of thermometer.On the other hand, digital thermometer is done a little change, promptly can be multiple differential digital thermometer.
Can the many of compensating circuit drift be by four-wire system thermistor linearization testing circuit (1) with digital thermometer (Fig. 1), temperature-measuring thermistor Rt, measuring resistance (or potentiometer) R
0And R
100, amplifier (2), periodic sampling three cuttves three throw switch K
1, K
2, K
3, keep capacitor C t, C
0, C
200And digital voltage panel table (3) composition that has removed internal reference voltage, the low input end INL of panel table is connected capacitor C with simulation ground end AGND
0, high input end INH connects capacitor C t, reference voltage terminal V
RFEConnect capacitor C
100
Owing to consider far connecing of thermistor, adopt four-wire system linearity test circuit.
When constituting the direct-reacting digital thermometer, get R
0=R
t(t=0 ℃), R
100=R
t(t=100 ℃) makes K
1, K
2, K
3Cycle connects successively, disconnects, and guarantees that each has only resistance to insert testing circuit constantly.Can obtain from the linearization testing circuit:
At R
tDuring access: voltage Vt=I(t on it) R(t ℃)=St+V
0
At R
0During access: voltage V on it
0=I(O) R(0 ℃)=V
0
At R
100During access: voltage V on it
100=I(100) R(100 ℃)
＝S·100℃＋V
0
I(t wherein)---the testing circuit output current.
S---testing circuit voltage, temperature control.
Vt, V
0, V
100Behind amplifier, import holding circuit, at capacitor C
t, C
0, C
100Last sustaining voltage respectively:
V
Ct＝A（St＋V
0）
V
CO＝A（V
0）
VC
100＝A（S·100℃＋V
0）
A---amplifier voltage gain wherein.
Sustaining voltage is input to digital voltage panel table (internal reference voltage is removed) more respectively
Digital display value=100.00 * (V
IN)/(V
RFE) (℃)
＝100.00× (V
ct-V
c0)/(V
c100-V
c0) 〔℃〕
＝100.00× (A(st+V
0)-AV
0)/(A(S.100℃+V
0)-AV
0) 〔℃〕
＝100.00× (t)/(100℃) 〔℃〕
＝t〔℃〕
In sum, the error of thermometer only comes from R
0And R
100, as long as select stable sufficiently high R
0And R
100Measuring resistance just can obtain the digital thermometer of desired precision.
Change measuring resistance R
0And R
100, this thermometer can become multiple differential digital thermometer easily.
When constituting the relative temperature value of differential direct-reading digital thermometer measuring media, as long as with R
0Change potentiometer into, to adjust initial temperature value; With R
100Change R into
fMeasuring resistance,
R
f＝ (S·Δt)/(I)
R
f---thermometer range resistance
S---testing circuit voltage, temperature control
I---testing circuit reference current
Δ t---get 10 ℃ or 100 ℃
When the differential thermometer range is got 10 ℃ less than 20 ℃
When the differential thermometer range is got 100 ℃ less than 200 ℃;
Again digital voltage panel table simulation ground end and low input end are disconnected back ground connection.Before changing, medium temperature adjusts R
0Potentiometer makes the panel table be shown as zero; When medium temperature changes, show to be the relative temperature value.
Constituting the timing of instantaneous differential direct-reading digital temperature, with R
0Change one and R into
tIdentical thermistor is with R
100Change R into
fMeasuring resistance, R
f=(S Δ t)/(I) (as mentioned above); Again digital voltage panel table simulation ground end and low input end are disconnected back ground connection.Two thermistors are inserted two test points, and the panel meter reading is two test point temperature approach.
The digital thermometer measuring accuracy height of using of energy compensating circuit drift more, circuit is simple, and cost is low, is convenient to implement, and has the function of multiple differential digital thermometer.
Realize K switch of the present invention
1, K
2, K
3Select cmos analog switch for use, inversion frequency is selected in about 500 hertz; Keep electric capacity to select the big capacitors of insulation resistance such as CL232 type for use, capacity is about 1 μ; Amplifier does not have specific (special) requirements.
Claims (3)
1, the digital thermometer of a kind of energy compensating circuit drift is by four-wire system thermistor linearization testing circuit (1), temperature-measuring thermistor R
t, measuring resistance (or potentiometer) R
0And R
100Amplifier (2), the periodic sampling K switch
1, K
2, K
3, keep capacitor C
t, C
0, C
100And digital voltage panel table (3) forms, and it is characterized in that using the digital voltmeter (3) of no internal reference voltage, holds to low input end of panel table (3) and simulation to be connected capacitor C
0, high input end connects capacitor C
t, reference voltage terminal connects C
100
2, digital thermometer according to claim 1 is characterized in that measuring resistance R
0Change potentiometer into, with measuring resistance R
100Change measuring resistance R into
f, digital voltage panel table simulation ground end and low input end are disconnected back ground connection, be differential direct-reading digital thermometer.
3, digital thermometer according to claim 1 is characterized in that measuring resistance R
0Change the thermistor identical into, with measuring resistance R with Rt
100Change measuring resistance R into
f, digital voltage panel table simulation ground end and low input end are disconnected back ground connection, be instantaneous differential direct-reading digital thermometer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 87209746 CN87209746U (en) | 1987-07-06 | 1987-07-06 | Multifunctional digital thermometer with drift compensation |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 87209746 CN87209746U (en) | 1987-07-06 | 1987-07-06 | Multifunctional digital thermometer with drift compensation |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN87209746U true CN87209746U (en) | 1988-02-03 |
Family
ID=4824782
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 87209746 Ceased CN87209746U (en) | 1987-07-06 | 1987-07-06 | Multifunctional digital thermometer with drift compensation |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN87209746U (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102010041897A1 (en) | 2010-10-03 | 2012-04-05 | Albert-Ludwigs-Universität Freiburg | Apparatus and method for temperature measurement in centrifugal-fluidic systems |
| CN106289559A (en) * | 2015-06-24 | 2017-01-04 | Ls产电株式会社 | For the method using the temperature drift compensation of the temperature measuring equipment of thermocouple |
| CN110608809A (en) * | 2018-06-14 | 2019-12-24 | 浙江智柔科技有限公司 | Temperature measuring device, module and method based on thermistor |
| CN113884931A (en) * | 2021-10-28 | 2022-01-04 | 傲普(上海)新能源有限公司 | Time drift compensation method of BMS (battery management system) |
-
1987
- 1987-07-06 CN CN 87209746 patent/CN87209746U/en not_active Ceased
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102010041897A1 (en) | 2010-10-03 | 2012-04-05 | Albert-Ludwigs-Universität Freiburg | Apparatus and method for temperature measurement in centrifugal-fluidic systems |
| WO2012046178A1 (en) | 2010-10-03 | 2012-04-12 | Albert-Ludwigs-Universität Freiburg | Temperature measurement in centrifugal - fluidic systems |
| CN106289559A (en) * | 2015-06-24 | 2017-01-04 | Ls产电株式会社 | For the method using the temperature drift compensation of the temperature measuring equipment of thermocouple |
| US10101217B2 (en) | 2015-06-24 | 2018-10-16 | Lsis Co., Ltd. | Method for temperature drift compensation of temperature measurement device using thermocouple |
| CN106289559B (en) * | 2015-06-24 | 2019-02-15 | Ls 产电株式会社 | Method for using the temperature drift compensation of the temperature measuring device of thermocouple |
| CN110608809A (en) * | 2018-06-14 | 2019-12-24 | 浙江智柔科技有限公司 | Temperature measuring device, module and method based on thermistor |
| CN110608809B (en) * | 2018-06-14 | 2021-06-15 | 浙江智柔科技有限公司 | Temperature measuring device, module and method based on thermistor |
| CN113884931A (en) * | 2021-10-28 | 2022-01-04 | 傲普(上海)新能源有限公司 | Time drift compensation method of BMS (battery management system) |
| CN113884931B (en) * | 2021-10-28 | 2023-06-23 | 傲普(上海)新能源有限公司 | Time drift compensation method of BMS system |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CE01 | Termination of patent right |