CN2791621Y - Digital pressure gauge with temperature compensating function - Google Patents
Digital pressure gauge with temperature compensating function Download PDFInfo
- Publication number
- CN2791621Y CN2791621Y CN 200420077278 CN200420077278U CN2791621Y CN 2791621 Y CN2791621 Y CN 2791621Y CN 200420077278 CN200420077278 CN 200420077278 CN 200420077278 U CN200420077278 U CN 200420077278U CN 2791621 Y CN2791621 Y CN 2791621Y
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- circuit
- temperature
- pressure gauge
- digital pressure
- temperature compensation
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Abstract
The utility model relates to a digital pressure gauge with a temperature compensating function. The digital pressure gauge with a circuit having low cost and temperature compensation is designed through thermistors. The magnification of an operational (OP) amplifier is changed by a negative temperature coefficient thermistor or a positive temperature coefficient thermistor. Thus, the utility model can ensure that the pressure accuracy of the digital pressure gauge in the operating temperature range obtains full scale output (%FSO (Full Scale Output)) of plus and minus one percent. The utility model is suitable for the pressure gauges with low cost and eligible accuracy.
Description
Technical field
The utility model relates to a kind of digital pressure gauge, especially refer to the tensimeter (pressure meter) that a kind of low-cost digital shows, have temperature compensation cheaply (temperaturecompensation) circuit, impel it under various environment temperatures, also can accurately measure the digital pressure gauge of pressure.
Background technology
Tensimeter uses the numeral demonstration value of reading to use a lot of years, as shown in Figure 1, be to use power circuit 10, pressure sensor 20, computing (OP) amplifier (Op Amp (OperationalAmplifier)) 30, analog-digital converter (ADC (Analog-to-Digital Converter)) 40, microprocessor (Microprocessor) 50 and liquid crystal display drive circuit (Liquid CrystalDisplay (LCD) Driver) 60, LCD (LCD) 601 and hummer 501 designs.
Tensimeter working pressure sensor (Pressure Sensor) 20 comes to convert to behind the pressure sensor electronic signal of simulation, after by OP amplifier 30 sensing signal being amplified again, be converted to digital signal through analog-digital converter 40, be presented on the LCD (LCD) 601 after doing signal Processing by microprocessor 50 again, can finish the tensimeter that numeral shows.Power circuit (powercircuit) 10 provides fixed voltage source or current source to pressure sensor 20, and hummer (buzzer) 501 is used for reminding user's various situations about should be noted that when the working pressure table.
Come again, pressure sensor 20 is presented at Fig. 2, it uses four piezoresistances (piezoresistors) 202～205 to link formation Wheatstone bridge (Whetstone bridge) 201 and is presented at Fig. 2, two piezoresistances 202 at Wheatstone bridge 201,204 can reduce resistance value along with the pressure increase of sensing, and at two other piezoresistance 203 of Wheatstone bridge 201,205 can increase resistance value along with the pressure increase of sensing, when this pressure sensor provides voltage by power circuit, two tie points (junction) 206,207 for providing electrical voltage point, at two other tie point 208,209 voltage difference and along with the pressure of sensing changes, and obtain the simulating signal of electronic type, can be processed into digital signal by microprocessor 50 and be presented on the LCD 601.
Electronic pressure table comparison mechanical compression table can obtain than higher accuracy and degree of stability, however the easy temperature influence of the more mechanical pressure sensor of the pressure sensor of piezoresistance formula, and produce bigger error.So manufacturer's (comprising NovaSensor, Sensortechnics etc.) of the pressure sensor of a lot of applying piezoelectrics resistance formulas all can the serviceability temperature compensating circuit, when the temperature change of pressure sensor, it is accurate poor by temperature-compensation circuit the force value that senses to be kept automatically.Two kinds of known temperature-compensation circuits are arranged below.
First kind of circuit as shown in Figure 3, utilize thermosensitive resistor and circuit 70 to be placed between power circuit 10 and the pressure sensor 20, pressure sensor 20 makes the piezoelectric electro resistive big because of temperature raises, so that the output span temperature coefficient (Temperature coefficient of outputspan) of pressure sensor 20 can raise with temperature and reduce, so utilize negative temperature coefficient (Negative TemperatureCoefficient (NTC)) thermistor Thermistor to diminish with temperature rising resistance value, the electric current that flows through pressure sensor 20 is increased, to export span temperature coefficient (Temperaturecoefficient of output span) compensation returns, allow pressure sensor 20 under different temperatures, obtain pressure value of reading accurately.
Second kind of circuit as shown in Figure 4, utilize diode circuit 80 to be placed between power circuit 10 and the pressure sensor 20, pressure sensor 20 makes the piezoelectric electro resistive big because of temperature raises, so that the output span temperature coefficient (Temperature coefficient of outputspan) of pressure sensor 20 can raise with temperature and reduce, so the diode (Diode) that utilizes negative temperature coefficient (Negative TemperatureCoefficient (NTC)) with temperature raise its forward voltage (ForwardVoltage) can diminish, the electric current that flows through pressure sensor 20 is increased, to export span temperature coefficient (Temperature coefficient of output span) compensation returns, allow pressure sensor 20 under different temperatures, obtain pressure value of reading accurately.
By above known techniques all utilize can temperature variant pressure sensor supply voltage reach effect temperature compensation, mainly be that temperature effect (Temperature Effecton Span) with the total pressure scope drops to minimum, but this kind temperature-compensation circuit is because of having reduced supply voltage, and pressure sensor is just diminished in the voltage output that identical pressure obtains, promptly be the sensitivity (Sensitivity) that has reduced this pressure sensor, need be at the bigger enlargement ratio of amplifier, and also can amplify another parameter zero point pressure off-set value (Zero PressureOffset) of pressure sensor temperature influence, make accuracy reduce, so traditional temperature compensation need need to increase cost and just can obtain better accuracy again to temperature effect (Temperature Effect on Offset) the increase compensating circuit of zero migration.
Summary of the invention
The utility model relates to a kind of digital pressure gauge with temperature compensation function, supply voltage at pressure sensor uses fixed voltage or current source, temperature-compensation circuit has two kinds of devices, be used to change the enlargement ratio of amplifier, can not reduce the sensitivity of pressure sensor, because of the enlargement ratio that changes amplifier compensates output span temperature coefficient (Temperature coefficient ofoutput span), also can compensate the temperature coefficient (Temperature coefficientof Zero Offset) of zero migration, so must not add compensating circuit in addition to the temperature effect (Temperature Effect onOffset) at zero point, can reduce cost, experimental result accuracy of its measurement in the temperature range of work can reach ± 1% full scale output (%FSO (Full Scale Output)), be suitable for low cost and the also satisfactory digital pressure gauge of accuracy.
The utility model is achieved in that
A kind of digital pressure gauge with temperature compensation function, it is characterized in that: described digital pressure gauge has operation amplifier circuit, and operation amplifier circuit is connected with thermosensitive resistor and circuit with resistance of using as the change enlargement ratio and the temperature compensation that can be used as output signal, the thermistor of this thermosensitive resistor and circuit with around temperature variation change its resistance, the enlargement ratio of operation amplifier circuit is changed thereupon.
This operation amplifier circuit is noninverting amplifying circuit.
This operation amplifier circuit is a see-saw circuit.
This operation amplifier circuit is the instrument amplifying circuit.
This operation amplifier circuit is the one-level amplifying circuit.
This operation amplifier circuit is a multistage amplifier circuit.
This thermosensitive resistor and circuit is a negative temperature coefficient.
This thermosensitive resistor and circuit is a positive temperature coefficient (PTC).
Temperature is meant environment temperature all around.
Temperature is meant the temperature of sensor chamber all around.
The beneficial effects of the utility model are: the digital pressure gauge with temperature compensation function of the present invention, by being connected with the enlargement ratio that thermosensitive resistor and circuit changes amplifier at its operation amplifier circuit, but can not reduce the sensitivity of pressure sensor; And, compensated output span temperature coefficient by the enlargement ratio that changes amplifier, also compensated the temperature coefficient of zero migration, so must not add compensating circuit in addition, reduced cost to the temperature effect at zero point, guaranteed manometric accuracy simultaneously again.
Description of drawings
Fig. 1 commonly uses low-cost tire gauge or manometric calcspar;
Fig. 2 is a calcspar of commonly using pressure sensor;
Fig. 3 is a calcspar of commonly using low-cost temperature compensation by thermistor circuit embodiments;
Fig. 4 is a calcspar of commonly using low-cost diode temperature compensating circuit;
Fig. 5 (a) commonly uses the calcspar of operation amplifier circuit with noninverting amplification embodiment;
Fig. 5 (b) commonly uses the calcspar of operation amplifier circuit with anti-phase amplification embodiment;
Fig. 5 (c) commonly uses operation amplifier circuit amplifies embodiment with instrument calcspar;
Fig. 6 (a) is of the present utility model with the calcspar with noninverting amplification embodiment of thermistor as temperature compensation;
Fig. 6 (b) is of the present utility model with the calcspar with anti-phase amplification embodiment of thermistor as temperature compensation;
Fig. 6 (c) is of the present utility model with the calcspar with instrument amplification embodiment of thermistor as temperature compensation;
Fig. 7 (a) is that the utility model is with the calcspar with noninverting amplification embodiment of thermistor as temperature compensation;
Fig. 7 (b) is that the utility model is with the calcspar with anti-phase amplification embodiment of thermistor as temperature compensation;
Fig. 7 (c) is that the utility model is with the calcspar with instrument amplification embodiment of thermistor as temperature compensation;
Symbol description:
10 power circuits
20 pressure sensors
201 Wheatstone bridges
202～205 piezoresistances
206～209 tie points
30 computings (OP) amplifier
40 analog-digital converters
50 microprocessors
501 hummers
60 liquid crystal display drive circuits
601 LCD (LCD)
70 thermosensitive resistor and circuits
80 diode circuits
90 noninverting amplifying circuits
901 differential amplifiers
91 see-saw circuits
911 differential amplifiers
92 instrument amplifying circuits
921 instrument amplifiers
1 non-inverting amplifier
11 differential amplifiers
2 see-saw circuits
21 differential amplifiers
3 instrument amplifying circuits
31 instrument amplifiers
4 thermosensitive resistor and circuits
5 noninverting amplifying circuits
51 differential amplifiers
6 see-saw circuits
61 differential amplifiers
7 instrument amplifying circuits
71 instrument amplifiers
8 thermosensitive resistor and circuits
R1 resistance
R2 resistance
Embodiment
Digital pressure gauge of the present utility model, improved at this manometric amplification circuits, promptly use thermistor, deciding can be with the multiplying power of the amplifying circuit of temperature change, this thermistor must and pressure sensor put together could the pressure sensor sensor present temperature, and this amplifying circuit is to be main circuit with computing (OP) amplifier.The enforcement illustration that sees also Fig. 5 (a), 5 (b), 5 (c) is that the differential amplifier 901,911 that generally constitutes with operational amplifier or instrument amplifier 921 cooperate resistance R 1, operation amplifier circuits such as noninverting amplifying circuit 90, see-saw circuit 91 and instrument amplifying circuit 92 that R2 was formed, and its input end then connects as known manometric power circuit 10 and pressure sensor 20.Wherein, resistance R 1 and the enlargement ratio relation of being inversely proportional to, resistance R 2 is proportional with enlargement ratio.
In down, promptly cooperate the embodiment of Fig. 5 (a), 5 (b), 5 (c), it is modified to Fig. 6 (a), 6 (b), 6 (c) and Fig. 7 (a), 7 (b), 7 (c), can utilize two kinds of temperature compensation means to change enlargement ratio so that the utility model to be described whereby:
First method is shown in Fig. 6 (a), figure (b), figure (c), it is the operation amplifier circuits such as noninverting amplifying circuit 1, see-saw circuit 2 and instrument amplifying circuit 3 that cooperate thermistors 4, resistance R 2 to be formed with the differential amplifier 11,21 of operational amplifier formation or instrument amplifier 31, and its input end connects power circuit 10 and pressure sensor 20.Wherein, pressure sensor 20 provides fixed voltage or electric current by power circuit 10, can convert the pressure of induction to output voltage, continue and utilize Fig. 6 (a), 6 (b), the noninverting amplifying circuit 1 of 6 (c), operation amplifier circuits such as see-saw circuit 2 and instrument amplifying circuit 3 come the design temperature compensation system to change the enlargement ratio of big device, as long as the resistance R 1 that thermosensitive resistor and circuit 4 is replaced general operation amplifier circuit (sees also Fig. 5 (a), 5 (b), shown in 5 (c)), when the temperature change of pressure sensor 20, the resistance value of the thermistor in the thermosensitive resistor and circuit 4 changes with it, can change above-mentioned noninverting amplifying circuit 1, the enlargement ratio of operation amplifier circuits such as see-saw circuit 2 and instrument amplifying circuit 3 is done the temperature compensation of output signal.When if the temperature coefficient of pressure sensor 20 is negative, the thermistor of these thermosensitive resistor and circuit 4 usefulness negative temperature coefficients; If the temperature coefficient of pressure sensor 20 is timing, the thermistor of these thermosensitive resistor and circuit 4 usefulness positive temperature coefficient (PTC)s.Design because of operation amplifier circuits such as above-mentioned noninverting amplifying circuit 1, see-saw circuit 2 and instrument amplifying circuits 3, except compensating the temperature effect of total pressure scope, the effect that the temperature effect of compensation off-set value at zero point is just arranged again, as long as, be suitable for low cost and the also satisfactory tensimeter of accuracy so use cheaply thermosensitive resistor and circuit 4 just can make in the accuracy of digital pressure gauge operating temperature range internal pressure at ± 1%FSO.
Wherein, this computing (OP) amplifier circuit can be one-level (Single-ended), secondary (Two-ended) or multistage amplifier circuits.In addition, the thermistor of thermosensitive resistor and circuit 4 can be placed on the wiring board or be placed on sensor chamber (Sensor housing), thermosensitive resistor and circuit is as the resistance that changes enlargement ratio whereby, with thermistor with around temperature (as the temperature of environment or sensor chamber (Sensor Housing)) produce its resistance variations, the multiplying power that makes this operational amplification circuit with change.
Second kind of device is shown in Fig. 7 (a), 7 (b), 7 (c), it is the operation amplifier circuits such as noninverting amplifying circuit 5, see-saw circuit 6 and instrument amplifying circuit 7 that cooperate thermistors 8, resistance R 1 to be formed with the differential amplifier 51,61 of operational amplifier formation or instrument amplifier 71, and its input end connects power circuit 10 and pressure sensor 20.Wherein, pressure sensor 20 provides fixed voltage or electric current by power circuit 10, can convert the pressure of induction to output voltage, continue and utilize Fig. 7 (a), 7 (b), the noninverting amplifying circuit 5 of 7 (c), operation amplifier circuits such as see-saw circuit 6 and instrument amplifying circuit 7 come the design temperature compensation system to change the enlargement ratio of amplifier, as long as the resistance R 2 that thermosensitive resistor and circuit 8 is replaced general operation amplifier circuit (sees also Fig. 5 (a), 5 (b), shown in 5 (c)), when the temperature change of pressure sensor 20, the resistance value of the thermistor in the thermosensitive resistor and circuit 4 changes with it, can change above-mentioned noninverting amplifying circuit 5, the enlargement ratio of operation amplifier circuits such as see-saw circuit 6 and instrument amplifying circuit 7 is done the temperature compensation of output signal.When if the temperature coefficient of pressure sensor 20 is negative, the thermistor of these thermosensitive resistor and circuit 8 usefulness positive temperature coefficient (PTC)s; If the temperature coefficient of pressure sensor 20 is timing, the thermistor of these thermosensitive resistor and circuit 8 usefulness negative temperature coefficients.Design because of operation amplifier circuits such as above-mentioned noninverting amplifying circuit 5, see-saw circuit 6 and instrument amplifying circuits 7, except compensating the temperature effect of total pressure scope, the effect that the temperature effect of compensation off-set value at zero point is just arranged again, as long as, be suitable for low cost and the also satisfactory tensimeter of accuracy so use cheaply thermosensitive resistor and circuit 8 just can make in the accuracy of digital pressure gauge operating temperature range internal pressure at ± 1%FSO.
Wherein, this computing (OP) amplifier circuit can be one-level (Single-ended), secondary (Two-ended) or multistage amplifier circuits.In addition, the thermistor of thermosensitive resistor and circuit 8 can be placed on the wiring board or be placed on sensor chamber (Sensor housing), thermosensitive resistor and circuit is as the resistance that changes enlargement ratio whereby, with thermistor with around temperature (as the temperature of environment or sensor chamber (Sensor Housing)) produce its resistance variations, the multiplying power that makes this operational amplification circuit with change.
Claims (10)
1. digital pressure gauge with temperature compensation function, it is characterized in that: described digital pressure gauge has operation amplifier circuit, and operation amplifier circuit is connected with thermosensitive resistor and circuit with resistance of using as the change enlargement ratio and the temperature compensation that can be used as output signal, the thermistor of this thermosensitive resistor and circuit with around temperature variation change its resistance, the enlargement ratio of operation amplifier circuit is changed thereupon.
2. the digital pressure gauge with temperature compensation function according to claim 1 is characterized in that: this operation amplifier circuit is noninverting amplifying circuit.
3. the digital pressure gauge with temperature compensation function according to claim 1 is characterized in that: this operation amplifier circuit is a see-saw circuit.
4. the digital pressure gauge with temperature compensation function according to claim 1 is characterized in that: this operation amplifier circuit is the instrument amplifying circuit.
5. the digital pressure gauge with temperature compensation function according to claim 1 is characterized in that: this operation amplifier circuit is the one-level amplifying circuit.
6. the digital pressure gauge with temperature compensation function according to claim 1 is characterized in that: this operation amplifier circuit is a multistage amplifier circuit.
7. the digital pressure gauge with temperature compensation function according to claim 1 is characterized in that: this thermosensitive resistor and circuit is a negative temperature coefficient.
8. the digital pressure gauge with temperature compensation function according to claim 1 is characterized in that: this thermosensitive resistor and circuit is a positive temperature coefficient (PTC).
9. the digital pressure gauge with temperature compensation function according to claim 1 is characterized in that: temperature is meant environment temperature all around.
10. the digital pressure gauge with temperature compensation function according to claim 1 is characterized in that: temperature is meant the temperature of sensor chamber all around.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200420077278 CN2791621Y (en) | 2004-08-17 | 2004-08-17 | Digital pressure gauge with temperature compensating function |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200420077278 CN2791621Y (en) | 2004-08-17 | 2004-08-17 | Digital pressure gauge with temperature compensating function |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN2791621Y true CN2791621Y (en) | 2006-06-28 |
Family
ID=36807684
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 200420077278 Expired - Fee Related CN2791621Y (en) | 2004-08-17 | 2004-08-17 | Digital pressure gauge with temperature compensating function |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN2791621Y (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TWI596323B (en) * | 2015-08-17 | 2017-08-21 | 宸鴻科技（廈門）有限公司 | A pressure-sensitive device |
| CN107290024A (en) * | 2016-03-31 | 2017-10-24 | 中核新能核工业工程有限责任公司 | A kind of radio frequency admittance level-sensing device with anti-jamming circuit |
| CN107655616A (en) * | 2017-09-13 | 2018-02-02 | 武汉中航传感技术有限责任公司 | The temperature compensation system and method for a kind of differential pressure pick-up |
-
2004
- 2004-08-17 CN CN 200420077278 patent/CN2791621Y/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TWI596323B (en) * | 2015-08-17 | 2017-08-21 | 宸鴻科技（廈門）有限公司 | A pressure-sensitive device |
| CN107290024A (en) * | 2016-03-31 | 2017-10-24 | 中核新能核工业工程有限责任公司 | A kind of radio frequency admittance level-sensing device with anti-jamming circuit |
| CN107655616A (en) * | 2017-09-13 | 2018-02-02 | 武汉中航传感技术有限责任公司 | The temperature compensation system and method for a kind of differential pressure pick-up |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20060628 Termination date: 20090917 |