CN205941448U - VOC gas sensor's concentration and temperature drift's compensating circuit - Google Patents
VOC gas sensor's concentration and temperature drift's compensating circuit Download PDFInfo
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- CN205941448U CN205941448U CN201620962015.0U CN201620962015U CN205941448U CN 205941448 U CN205941448 U CN 205941448U CN 201620962015 U CN201620962015 U CN 201620962015U CN 205941448 U CN205941448 U CN 205941448U
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Abstract
The utility model discloses a VOC gas sensor's concentration and temperature drift's compensating circuit, compensating circuit include VOC light ion sensor, the AD converter, and VOC light ion sensor passes through measuring bridge with the AD converter and is connected, and the AD converter is connected with the singlechip with temperature sensor, at first let in the mark gas of different concentration to VOC photoion gas sensor under normal atmospheric temperature, carry out the record with the output voltage value that corresponds to confirm its change rule who follows concentration, next carries out the experiment of high low temperature to confirm the curve of its output valve along with temperature drift, recycle temperature sensor and carry out the real -time measurement to the operating temperature of instrument, use single chip microcomputer program to carry out software compensation calculation to VOC photoion gas sensor in two dimensions of concentration and temperature, solved the gaseous sensing of VOC photoion and followed the measuring error problem that gas strength, temperature drift led to the fact.
Description
【Technical field】
This utility model is related to gas analyses field, the specifically compensation of the concentration of VOC gas sensor and temperature drift
Circuit.
【Background technology】
VOC is the abbreviation of " Volatile Organic Compounds ", you can volatile organic compounds, such as toluene, ethylbenzene, benzene
Ethylene, formaldehyde, ethanol, tetradecane, TVOC etc..
VOC outdoor is essentially from fuel combustion and transportation；Indoor essentially from the combustion products such as coal-fired and natural gas,
Smoking, heating and the cooking etc. obtain smog, building and ornament materials, furniture, the discharge of household electrical appliance, cleaning agent and human body itself
Deng.
A lot of instrument are sensitivity and the zero points adjusting sensor by potentiometer in the market, that is, will sense
Device is regarded as linear convergent rate device in itself, but a lot of gas sensor is nonlinear characteristic, and potentiometer adjusts and can not solve to pass
The nonlinear compensation problem of sensor, and potentiometer itself also has temperature drift problems.And VOC sensor is in Pressure, Concentration, Temperature two
It is all nonlinear in dimension.
【Utility model content】
For solving the problems, such as prior art, the purpose of this utility model is to provide the concentration of VOC gas sensor
With the compensation circuit of temperature drift, this utility model can be directed to VOC photoion sensor 2 dimension the non-linear compensation carrying out,
And all of compensating parameter is stored, also eliminate potentiometer.
The technical scheme that this utility model is adopted is as follows：
The concentration of VOC gas sensor and the compensation circuit of temperature drift, including single-chip microcomputer be used for obtaining VOC gas dense
The VOC photoion sensor of degree, VOC photoion sensor is connected with measuring bridge, measuring bridge is used for obtaining VOC photoion
Output voltage signal when sensor changes with gas concentration, measuring bridge is connected with for being transformed to measure number voltage signal
According to A/D converter, A/D converter is connected with single-chip microcomputer, and single-chip microcomputer is also associated with temperature sensor.
Described A/D converter divides sigma-delta A/D converter for 16 potential differences.
Described single-chip microcomputer is the single-chip microcomputer of built-in segment liquid crystal drive module.
Described measuring bridge includes resistance R31 and the electric capacity being connected successively with the output pin of VOC photoion sensor
The other end ground connection of C26, electric capacity C26, the intermediate point between resistance R31 and electric capacity C26 connects to be rectified to the input of A/D converter
Pole；
Also include resistance R7 and resistance R8, resistance R7 and resistance R8 series connection, the other end of resistance R7 is sensed with VOC photoion
The power supply that device power pins are connect connects, the other end ground connection of resistance R8, and the intermediate point between resistance R7 and resistance R8 connects successively
It is connected to resistance R32 and electric capacity C28, the other end ground connection of electric capacity C28, the intermediate point between resistance R32 and electric capacity C28 connects to A/
The input cathode of D transducer, is connected with electric capacity C27 between the input anode of A/D converter and input cathode.
Described supply voltage is 3V, resistance R7=10K Ω, resistance R8=180 Ω, resistance R31=R32=10K Ω, electricity
Hold C26=C28=1 μ F, electric capacity C27=10 μ F.
Described VOC photoion sensor is connected with measuring bridge by terminal.
Compared with prior art, this utility model has the advantages that：
The concentration of VOC gas sensor of the present utility model and the compensation circuit of temperature drift are sensed by VOC photoion
Device obtains VOC gas concentration, then obtains output voltage letter when VOC photoion sensor changes with gas concentration by measuring bridge
Number, then the voltage signal that measuring bridge exports is transformed to by measurement data by A/D converter, turned by Single-chip Controlling A/D
Parallel operation measures and processes measurement data, is transferred to by the temperature of temperature sensor measurement VOC gas and by temperature information
Single-chip microcomputer.
【Brief description】
Fig. 1 (a) is the concentration of VOC gas sensor of the present utility model and the compensation circuit figure of temperature drift；Fig. 1 (b)
Schematic diagram for temperature sensor；
Fig. 2 is output voltage under the room temperature that compensation circuit of the present utility model records-concentration relationship curve chart；
Fig. 3 (a) is the temperature and electricity during the different temperatures test of the variable concentrations of compensation circuit detection of the present utility model
Graph of a relation between pressure output, Fig. 3 (b) is temperature-voltage when compensation circuit figure of the present utility model compensates to measurement data
Curve matching figure, Fig. 3 (c) is process by the compensation circuit figure of utility model in the different temperatures test of variable concentrations for the basis
The temperature of normalized and voltage compensation figure, Fig. 3 (d) is dense in difference when this is compensated by the compensation circuit figure of utility model
Temperature-voltage-PPM during the different temperatures test of degree compensates figure.
【Specific embodiment】
Come below in conjunction with the accompanying drawings this utility model is further described.
As shown in Fig. 1 (a) and Fig. 1 (b), the concentration of VOC gas sensor of the present utility model and the compensation of temperature drift
Circuit, including：VOC photoion sensor, for obtaining VOC gas concentration；Measuring bridge, for obtaining VOC photoion sensing
Output voltage signal when device changes with gas concentration；16 potential differences divide sigma-delta A/D converter, for being transformed to survey voltage signal
Amount data；The single-chip microcomputer of built-in segment liquid crystal drive module, for control A/D converter to measure and process measurement data with
And control display to show；Temperature sensor, is transferred to single-chip microcomputer for measurement temperature and by temperature information；
Measuring bridge of the present utility model includes the resistance R31 being connected successively with the output pin of VOC photoion sensor
With electric capacity C26, the other end ground connection of electric capacity C26, the intermediate point between resistance R31 and electric capacity C26 connects defeated to A/D converter
Enter proper pole；
Also include resistance R7 and resistance R8, resistance R7 and resistance R8 series connection, the other end of resistance R7 is sensed with VOC photoion
The power supply that device power pins are connect connects, the other end ground connection of resistance R8, and the intermediate point between resistance R7 and resistance R8 connects successively
It is connected to resistance R32 and electric capacity C28, the other end ground connection of electric capacity C28, the intermediate point between resistance R32 and electric capacity C28 connects to A/
The input cathode of D transducer, is connected with electric capacity C27 between the input anode of A/D converter and input cathode.
The power pins of VOC photoion sensor of the present utility model, grounding pin and output pin respectively with terminal 3
Foot, 2 feet and 1 foot connect, and 3 feet of terminal connect+3V regulated power supply, and 1 foot grounding pin of terminal connects simulation ground, 2 feet of terminal according to
Secondary connecting resistance R31, electric capacity C26 form low-pass filtering to ground, and to leach poor common mode disturbances, resistance R31 and electric capacity C26 intermediate point connect
+ VIN the foot of A/D converter, that is, the output voltage of sensor ultimately lead to AD converter input anode；
Resistance R7, resistance R8 warp+3V regulated power supply partial pressure, as the zero compensation voltage of sensor, through resistance R32 and electricity
Hold C28 to disturb with filtering common mode, resistance R32 and electric capacity C28 intermediate point connect the-VIN foot of A/D converter, i.e. dividing point output electricity
Pressure ultimately leads to the negative terminal of A/D converter input.+ VIN and-VIN that electric capacity C27 is connected on A/D converter are indirectly, as differential mode
Filter capacitor；
Wherein R7=10K Ω, R8=180 Ω, the result of partial pressure is 53mv, and the zero point in this, as sensor output is offset
Voltage, and resistance R7, resistance R8 adopt thousand-island forest park precision resistance, R31=R32=10K Ω, C26=C28=1 μ F,
C27=10 μ F.
It is right respectively that the compensation circuit compensation method of the concentration of VOC gas sensor of the present utility model and temperature drift is passed through
VOC photoion gas sensor carries out different temperatures test and the variable concentrations gas test under room temperature of variable concentrations, obtains and surveys
Amount data, further according to measurement data respectively to VOC photoion gas sensor output with concentration change nonlinear data and
Drift data with temperature carries out curve fitting, and carries out linear compensation in two dimensions respectively.
VOC gas sensor measuring bridge of the present utility model and temperature sensor circuit, collectively as the sensing of instrument
Device part；
Not using zero potentiometer in the middle of design, but record the zero of sensor with the EPROM of single-chip microcomputer when demarcating
Point voltage, and in measurement process, zero-point voltage is cut；
Compensation circuit of the present utility model based on data acquisition, storage, compensate total word arithmetic mode compensation method,
Do not adjust these hardware of potentiometer using zero potentiometer and gain sensitivity；
The A/D converter that this utility model adopts divides sigma-delta A/D converter for 16 potential differences, and its feature is that inside can be compiled
Journey gain controller PGA can carry out gain control by single-chip microcomputer, eliminates external arithmetic amplifier circuit, so that the circuit of system is set
Meter is more succinct；
It is customization section type liquid crystal display that this utility model uses liquid crystal display, and its control is flexible, low in energy consumption, and it is aobvious
Show that content is to aim at this Project design, simplify programming difficulty, reduce the power consumption of system, the use of single-chip microcomputer is built-in segmentation
The single-chip microcomputer of liquid crystal driver module；
Parameter of the present utility model includes zero point and penalty coefficient is stored in the middle of the EEPROM that carries inside single-chip microcomputer；
When VOC sensor works under different concentration environment and temperature environment, internal software compensation program can root
Output valve and current operating temperature value according to its corresponding concentration carry out two-dimentional compensation operation, draw final PPM indicating value；
Feature：By equal for all of measurement result digitized, and compensated using software, and all of instrument parameter is entered
Row power down preserves, and temperature change is measured in real time and sensor measurement is compensated.
Compensation circuit of the present utility model is passed through the mark of variable concentrations first at normal temperatures to VOC photoion gas sensor
Gas, corresponding output voltage values are recorded, and determine its Changing Pattern with concentration；Next carries out high/low temperature experiment,
To determine the curve with temperature drift for its output valve；Recycle temperature sensor that the operating temperature of instrument is measured in real time,
Using Single Chip Microcomputer (SCM) program, in concentration and two dimensions of temperature, software compensation calculating is carried out to VOC photoion gas sensor, solution
The measurement error problem that VOC photoion gas sensing of having determined causes with gas concentration, temperature drift.
As shown in Fig. 2 output voltage-concentration relationship curve chart under the room temperature recording for compensation circuit of the present utility model,
Be passed through variable concentrations value gas when, the corresponding relation curve between output voltage and each concentration, can be right according to this curve
VOC photoion gas sensor compensates with the non-linear of concentration change.
As shown in Fig. 3 (a) to Fig. 3 (d) it is shown that compensation circuit of the present utility model compensate when temperature drift and temperature
Drift trimming process, is passed through the gas of variable concentrations value, and does high/low temperature experiment, and sensor output voltage value is normalized
Process, and carry out curve fitting, non-linear benefit can be carried out to the temperature drift of VOC sensor output according to this Changing Pattern
Repay.
Using the concentration of VOC gas sensor and the compensation method of temperature drift of utility model, comprise the steps：Point
Variable concentrations gas test under the other different temperatures test that VOC photoion gas sensor is carried out with variable concentrations and room temperature, obtains
Measurement data being normalized, further according to measurement data respectively to the output of VOC photoion gas sensor with dense
Spend the nonlinear data of change and carry out curve fitting with the drift data of temperature, and carry out linearisation in two dimensions respectively
Compensate；
The process of linear compensation is：
First the concentration change rule of VOC gas is compensated, concentration offsets result=sensor actual measurement magnitude of voltage × F
(consistence), wherein F (consistence) is the fitting function with input concentration Changing Pattern for the VOC sensor；
Temperature drift to VOC gas compensates again, exports PPM value=concentration offsets result × F
(temperature), wherein F (temperature) is the fitting function that VOC sensor varies with temperature rule；
After obtaining exporting PPM value, then to the data drift in some temperature ranges (temperature range rising and falling as temperature data)
Shift-in line correction, final output PPM value=export PPM value+K (temp []), wherein K (temp []) refers to local temperature
The offset that data fluctuating in scope temp [] is modified, is modified according to experimental result, in the hope of more accurately PPM
Indicating value.
Because the basic step according to method of least square compares for the amount of calculation that is fitted of experiment curv of sensor
Greatly, so data processing is carried out using Matlab, so not only can reduce the calculating process of complexity, but also can ensure that relatively
High computational accuracy.
Compensation result is as shown in table 1：
| Time | Temperature DEG C | Gas 11PPM | Gas 99.5PPM | Gas 503PPM |
| On June 07 09:45 | 20 | 10.7 | 99.8 | 504.2 |
| On June 07 10:49 | 10 | 11.0 | 99.6 | 504.1 |
| On June 07 11：50 | 0 | 11.1 | 100.5 | 503.0 |
| On June 07 13:10 | -10 | 10.6 | 99.8 | 502.3 |
| On June 07 14:28 | -20 | 10.8 | 99.5 | 501.8 |
| On June 07 15:30 | -30 | 10.5 | 99.5 | 500.0 |
| On June 07 16:40 | -40 | 10.4 | 99.4 | 498.0 |
| On June 08 10:30 | 20 | 10.9 | 99.8 | 505.2 |
| On June 08 11:50 | 30 | 10.7 | 100.6 | 505.1 |
| On June 08 13:10 | 40 | 11.2 | 101.5 | 506.0 |
| On June 08 15:20 | 50 | 12.0 | 102.2 | 506.3 |
| On June 08 16:20 | 60 | 12.1 | 102.5 | 507.8 |
| On June 08 17:30 | 70 | 12.6 | 103.1 | 509.0 |
Table 1.
Claims (6)
- The compensation circuit of the concentration of 1.VOC gas sensor and temperature drift is it is characterised in that including single-chip microcomputer and being used for obtaining The VOC photoion sensor of VOC gas concentration, VOC photoion sensor is connected with measuring bridge, measuring bridge is used for obtaining Output voltage signal when VOC photoion sensor changes with gas concentration, measuring bridge is connected with for becoming voltage signal It is changed to the A/D converter of measurement data, A/D converter is connected with single-chip microcomputer, single-chip microcomputer is also associated with temperature sensor.
- 2. the concentration of VOC gas sensor according to claim 1 and the compensation circuit of temperature drift it is characterised in that Described A/D converter divides sigma-delta A/D converter for 16 potential differences.
- 3. the concentration of VOC gas sensor according to claim 1 and the compensation circuit of temperature drift it is characterised in that Described single-chip microcomputer is the single-chip microcomputer of built-in segment liquid crystal drive module.
- 4. the concentration of VOC gas sensor according to claim 1 and the compensation circuit of temperature drift it is characterised in that Described measuring bridge includes resistance R31 and the electric capacity C26 being connected successively, electric capacity with the output pin of VOC photoion sensor The other end ground connection of C26, the intermediate point between resistance R31 and electric capacity C26 connects to the input anode of A/D converter；Also include resistance R7 and resistance R8, resistance R7 and resistance R8 series connection, the other end of resistance R7 and VOC photoion sensor electricity The power supply that source pin is connect connects, the other end ground connection of resistance R8, and the intermediate point between resistance R7 and resistance R8 is connected with turn The other end ground connection of resistance R32 and electric capacity C28, electric capacity C28, the intermediate point between resistance R32 and electric capacity C28 connects and turns to A/D The input cathode of parallel operation, is connected with electric capacity C27 between the input anode of A/D converter and input cathode.
- 5. the concentration of VOC gas sensor according to claim 4 and the compensation circuit of temperature drift it is characterised in that Described supply voltage is 3V, resistance R7=10K Ω, resistance R8=180 Ω, resistance R31=R32=10K Ω, electric capacity C26= C28=1 μ F, electric capacity C27=10 μ F.
- 6. the concentration of VOC gas sensor according to claim 1 and the compensation circuit of temperature drift it is characterised in that Described VOC photoion sensor is connected with measuring bridge by terminal.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201620962015.0U CN205941448U (en) | 2016-08-26 | 2016-08-26 | VOC gas sensor's concentration and temperature drift's compensating circuit |
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|---|---|---|---|
| CN201620962015.0U CN205941448U (en) | 2016-08-26 | 2016-08-26 | VOC gas sensor's concentration and temperature drift's compensating circuit |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106093178A (en) * | 2016-08-26 | 2016-11-09 | 西安鼎研科技有限责任公司 | The concentration of VOC gas sensor and the compensation circuit of temperature drift and method |
| CN109557130A (en) * | 2017-09-25 | 2019-04-02 | 中国石油化工股份有限公司 | A kind of measurement and control method for detection gas thermal conductivity |
| CN113888841A (en) * | 2021-12-08 | 2022-01-04 | 成都千嘉科技有限公司 | Gas alarm system |
-
2016
- 2016-08-26 CN CN201620962015.0U patent/CN205941448U/en active Active
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106093178A (en) * | 2016-08-26 | 2016-11-09 | 西安鼎研科技有限责任公司 | The concentration of VOC gas sensor and the compensation circuit of temperature drift and method |
| CN109557130A (en) * | 2017-09-25 | 2019-04-02 | 中国石油化工股份有限公司 | A kind of measurement and control method for detection gas thermal conductivity |
| CN113888841A (en) * | 2021-12-08 | 2022-01-04 | 成都千嘉科技有限公司 | Gas alarm system |
| CN113888841B (en) * | 2021-12-08 | 2022-03-11 | 成都千嘉科技股份有限公司 | Gas alarm system |
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| CP03 | Change of name, title or address |
Address after: The new industrial park building 710065 Shaanxi province Xi'an City Station Road No. 22 Building 1 layer two Patentee after: XI'AN DINGYAN TECHNOLOGY CO.,LTD. Address before: The new industrial park building 710065 Shaanxi province Xi'an City Station Road, No. 22 Patentee before: XIAN DINGYAN TECHNOLOGY Co.,Ltd. |
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| PE01 | Entry into force of the registration of the contract for pledge of patent right | ||
| PE01 | Entry into force of the registration of the contract for pledge of patent right |
Denomination of utility model: Compensation circuit for concentration and temperature drift of VOC gas sensor Effective date of registration: 20201109 Granted publication date: 20170208 Pledgee: Pudong Development Bank of Shanghai Limited by Share Ltd. Xi'an branch Pledgor: XI'AN DINGYAN TECHNOLOGY Co.,Ltd. Registration number: Y2020610000200 |
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Date of cancellation: 20211125 Granted publication date: 20170208 Pledgee: Pudong Development Bank of Shanghai Limited by Share Ltd. Xi'an branch Pledgor: XI'AN DINGYAN TECHNOLOGY CO.,LTD. Registration number: Y2020610000200 |
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Denomination of utility model: Compensation circuit for concentration and temperature drift of VOC gas sensor Effective date of registration: 20211201 Granted publication date: 20170208 Pledgee: Pudong Development Bank of Shanghai Limited by Share Ltd. Xi'an branch Pledgor: XI'AN DINGYAN TECHNOLOGY CO.,LTD. Registration number: Y2021610000379 |
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Date of cancellation: 20221215 Granted publication date: 20170208 Pledgee: Pudong Development Bank of Shanghai Limited by Share Ltd. Xi'an branch Pledgor: XI'AN DINGYAN TECHNOLOGY CO.,LTD. Registration number: Y2021610000379 |
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Denomination of utility model: Compensation Circuit for Concentration and Temperature Drift of VOC Gas Sensor Effective date of registration: 20221220 Granted publication date: 20170208 Pledgee: Pudong Development Bank of Shanghai Limited by Share Ltd. Xi'an branch Pledgor: XI'AN DINGYAN TECHNOLOGY CO.,LTD. Registration number: Y2022610000815 |