CN109470745A - The method of dual sensor joint-detection volatile organic gases - Google Patents
The method of dual sensor joint-detection volatile organic gases Download PDFInfo
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- CN109470745A CN109470745A CN201811629606.6A CN201811629606A CN109470745A CN 109470745 A CN109470745 A CN 109470745A CN 201811629606 A CN201811629606 A CN 201811629606A CN 109470745 A CN109470745 A CN 109470745A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/02—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance
- G01N27/04—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance
- G01N27/12—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance of a solid body in dependence upon absorption of a fluid; of a solid body in dependence upon reaction with a fluid, for detecting components in the fluid
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N25/00—Investigating or analyzing materials by the use of thermal means
- G01N25/18—Investigating or analyzing materials by the use of thermal means by investigating thermal conductivity
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Abstract
The invention discloses the methods of dual sensor joint-detection volatile organic gases, detect volatile organic gases using semiconductor transducer and thermal conductivity gas sensor.Semiconductor responds preferably exhausted volatile organic gases, and lasts a long time, but the linearity is poor；The thermal conductivity sensor linearity is preferable, and the service life is long, but has response to all gas, and associated detection technique can be realized to escaping gas selectivity, the linearity and long-life.Associated detection technique scheme can extend detector using the time, substantially reduce the maintenance cost of user.
Description
Technical field
The present invention relates to a kind of methods of dual sensor joint-detection volatile organic gases.
Background technique
Volatile organic gases detection mode is mainly semiconductor transducer, thermal conductivity sensor and PID sensor, is partly led
It is poor that body senses dominant linear degree, the thermal conductivity sensor and PID sensor linearity is good but thermal conductivity sensor poor selectivity, PID make
It is shorter (1 year) with the service life.In order to solve the problems, such as selectivity, the linearity and long-life, sensed using semiconductor transducer and thermal conductivity
Associated detection technique.
Summary of the invention
It is an object of the invention to overcome the deficiencies of the prior art and provide a kind of dual sensor joint-detection volatility is organic
The method of gas.
The purpose of the present invention is achieved through the following technical solutions:
The method of dual sensor joint-detection volatile organic gases is passed by semiconductor sensor circuit and thermal conductivity gas
Sensor circuit detects volatile organic gases；
Semiconductor sensor circuit includes semiconductor transducer and semiconductor signal processing circuit；Thermal conductivity gas sensor electricity
Road includes thermal conductivity gas sensor and thermal conductivity sensor signal processing circuit；
Semiconductor sensor circuit and thermal conductivity gas sensor circuit are respectively connected to single-chip microcontroller.
It is preferred that semiconductor transducer qualitative detection volatile organic gases.
It is preferred that thermal conductivity gas sensor quantitative detection all gas.
It is preferred that semiconductor transducer is only used as threshold decision, thermal conductivity sensor is exported as final concentration, when
When containing volatile organic matter in environment, semiconductor transducer test side voltage can rise, when voltage is more than certain threshold value, starting
Thermal conductivity sensor voltage output, to be converted to the output of detector concentration.
It is preferred that semiconductor sensor circuit includes resistance R1-R4, capacitor C1 and C2, semiconductor transducer.
It is preferred that No. 3 of semiconductor transducer connect 5V power supply with No. 4 pins；
No. 1 pin of semiconductor transducer is separately connected resistance R2-R4, and No. 2 pins of semiconductor transducer are separately connected
Resistance R1 and resistance R2；
It is connected after resistance R1 and capacitor C1 connection with single-chip microcontroller；
Resistance R3 ground connection, resistance R4 form the end SHORT, the other end ground connection of capacitor C2 after connecting with capacitor C2.
It is preferred that thermal conductivity gas sensor circuit includes resistance R5-R19, capacitor C3-C10, thermal conductivity gas sensing
Device, amplifier U1 and U2.
It is preferred that No. 7 pins and No. 8 pin serial connections of thermal conductivity gas sensor, No. 4 of thermal conductivity gas sensor
Pin and No. 5 pin serial connections；
No. 1 pin of thermal conductivity gas sensor is separately connected resistance R6, R9 and R12, No. 2 pins of thermal conductivity gas sensor
Ground connection, No. 3 pins of thermal conductivity gas sensor are grounded by resistance R10, No. 6 pins ground connection of thermal conductivity gas sensor；
Resistance R6, R7, R5 and capacitor C3 and C4 link together, another termination 5V power supply of resistance R5, capacitor C3 and
The other end of C4 is grounded, and resistance R7 and resistance R8 series connection, the other end of resistance R8 are separately connected resistance R9, resistance R13, resistance
No. 2 pins of R10 and thermal conductivity gas sensor；
The inverting input terminal of amplifier U1 is separately connected resistance R11 and R14, and resistance R11 ground connection, resistance R14, which is connected to, to be put
The output end of big device U1, the positive power source terminal of amplifier U1 are separately connected resistance R15 and capacitor C6, and resistance R15 connects 5v power supply, capacitor
C6 ground connection, the negative power end ground connection of amplifier U1；The non-inverting input terminal of amplifier U1 is separately connected resistance R12 and capacitor C5, electricity
The other end for holding C5 is separately connected the non-inverting input terminal of resistance R13 and amplifier U2；
The non-inverting input terminal of amplifier U2 is grounded by capacitor C9, the negative voltage side ground connection of amplifier U2, amplifier U2's
Resistance R16 is set between inverting input terminal and the output end of amplifier U1, and the inverting input terminal of amplifier U2 is also respectively connected with electricity
Hold the output end that C7 and resistance R17, capacitor C7 and resistance R17 are connected to amplifier U2, the positive voltage terminal of amplifier U2 connects respectively
Connecting resistance R18 and capacitor C8, resistance R18 connection 5v power supply, capacitor C8 ground connection；Amplifier U2's connect with resistance R19, resistance
R19 is connected with capacitor C10, capacitor C10 ground connection, wherein draw AD_Signal on the bus of resistance R19 and capacitor C10
End.
The beneficial effects of the present invention are: semiconductor responds preferably exhausted volatile organic gases, and last a long time, but line
Property degree is poor；The thermal conductivity sensor linearity is preferable, and the service life is long, but has response to all gas, and associated detection technique can be realized
To escaping gas selectivity, the linearity and long-life.Associated detection technique scheme can extend detector using the time, greatly
The big maintenance cost for reducing user.
Detailed description of the invention
Fig. 1 is operation principle schematic diagram of the present invention；
Fig. 2 is semiconductor sensor circuit；
Fig. 3 is thermal conductivity gas sensor circuit.
Specific embodiment
Technical solution of the present invention is described in further detail with reference to the accompanying drawing, but protection scope of the present invention is not limited to
It is as described below.
As shown in Figure 1, the method for dual sensor joint-detection volatile organic gases, by semiconductor sensor circuit and
Thermal conductivity gas sensor circuit detects volatile organic gases；
Semiconductor sensor circuit includes semiconductor transducer and semiconductor signal processing circuit；Thermal conductivity gas sensor electricity
Road includes thermal conductivity gas sensor and thermal conductivity sensor signal processing circuit；
Semiconductor sensor circuit and thermal conductivity gas sensor circuit are respectively connected to single-chip microcontroller (preferably single-chip microcontroller minimum system
System, for completing collecting sensor signal and algorithm process).
In a preferred embodiment, semiconductor transducer qualitative detection volatile organic gases.
In a preferred embodiment, thermal conductivity gas sensor quantitative detection all gas (including the organic gas of volatility
Body).
In a preferred embodiment, semiconductor transducer is only used as threshold decision, and thermal conductivity sensor is as final concentration
Output, when containing volatile organic matter in environment, semiconductor transducer test side voltage can rise, when voltage is more than certain threshold
Value starts thermal conductivity sensor voltage output, to be converted to the output of detector concentration.
In a preferred embodiment, semiconductor sensor circuit includes resistance R1-R4, capacitor C1 and C2, and semiconductor passes
Sensor (SENSOR in Fig. 2, preferably TGS2602), connection relationship is as shown in Figure 2:
No. 3 of semiconductor transducer connect 5V power supply with No. 4 pins；
No. 1 pin of semiconductor transducer is separately connected resistance R2-R4, and No. 2 pins of semiconductor transducer are separately connected
Resistance R1 and resistance R2；
It is connected after resistance R1 and capacitor C1 connection with single-chip microcontroller；
Resistance R3 ground connection, resistance R4 form the end SHORT, the other end ground connection of capacitor C2 after connecting with capacitor C2.This implementation
The component parameters of example are shown in Fig. 2.
In a preferred embodiment, thermal conductivity gas sensor circuit includes resistance R5-R19, capacitor C3-C10, thermal conductivity gas
Body sensor (SENSOR in Fig. 3, preferably TCS208F), amplifier U1 and U2, connection relationship such as Fig. 3 between each element
It is shown:
No. 7 pins and No. 8 pin serial connections of thermal conductivity gas sensor, No. 4 pins and No. 5 pins of thermal conductivity gas sensor
Series connection；
No. 1 pin of thermal conductivity gas sensor is separately connected resistance R6, R9 and R12, No. 2 pins of thermal conductivity gas sensor
Ground connection, No. 3 pins of thermal conductivity gas sensor are grounded by resistance R10, No. 6 pins ground connection of thermal conductivity gas sensor；
Resistance R6, R7, R5 and capacitor C3 and C4 link together, another termination 5V power supply of resistance R5, capacitor C3 and
The other end of C4 is grounded, and resistance R7 and resistance R8 series connection, the other end of resistance R8 are separately connected resistance R9, resistance R13, resistance
No. 2 pins of R10 and thermal conductivity gas sensor；
The inverting input terminal of amplifier U1 is separately connected resistance R11 and R14, and resistance R11 ground connection, resistance R14, which is connected to, to be put
The output end of big device U1, the positive power source terminal of amplifier U1 are separately connected resistance R15 and capacitor C6, and resistance R15 connects 5v power supply, capacitor
C6 ground connection, the negative power end ground connection of amplifier U1；The non-inverting input terminal of amplifier U1 is separately connected resistance R12 and capacitor C5, electricity
The other end for holding C5 is separately connected the non-inverting input terminal of resistance R13 and amplifier U2；
The non-inverting input terminal of amplifier U2 is grounded by capacitor C9, the negative voltage side ground connection of amplifier U2, amplifier U2's
Resistance R16 is set between inverting input terminal and the output end of amplifier U1, and the inverting input terminal of amplifier U2 is also respectively connected with electricity
Hold the output end that C7 and resistance R17, capacitor C7 and resistance R17 are connected to amplifier U2, the positive voltage terminal of amplifier U2 connects respectively
Connecting resistance R18 and capacitor C8, resistance R18 connection 5v power supply, capacitor C8 ground connection；Amplifier U2's connect with resistance R19, resistance
R19 is connected with capacitor C10, capacitor C10 ground connection, wherein draw AD_Signal on the bus of resistance R19 and capacitor C10
It holds (i.e. AD_Signal WST in Fig. 3).The component parameters of the present embodiment are shown in Fig. 3.Wherein the parameter of R5, R15 and R18 are 10
Ohm.In another embodiment, R5, R15 and R18 directly cancel, and are replaced by conducting wire, i.e. the ginseng of R5, R15 and R18 in Fig. 3
Number is 0 ohm (cancelling corresponding resistor setting).
Semiconductor transducer working principle is when environment contains volatile organic matter, and sensor resistance can be dense with gas
Degree increases and reduces, and adds a resistance in output end, is changed by test resistance both end voltage to judge whether environment contains
Volatile organic matter；
Thermal conductivity working principle is detected according to different material thermal conductivity difference in environment, when leaked out in environment with
When environment different material, the thermal conductivity of environment can change, and thermal conductivity variation can cause thermal conductivity sensor resistance variations, pass through
Wheatstone bridge detects output voltage, to detect the concentration of environment.
Semiconductor transducer needs to be monitored its fire end and working end voltage for judging that sensor is when working
It is no to be in normal condition, therefore CHECK output voltage is for judging whether sensor heating is intact, SHORT output voltage is used for
Start thermal conductivity sensor voltage output, so that concentration be calculated and be shown by thermal conductivity sensor output voltage.Therefore, semiconductor
The end CHECK, SHORT and thermal conductivity signal output end are separately connected the AD thief hatch of single-chip microcontroller, by single-chip microcontroller to thermal conductivity voltage
It is processed into concentration and uploads to detector display, finally show concentration.
Present invention has an advantage that
1. volatile organic gases selectivity can be solved using associated detection technique；
2. detector output linearity degree can be solved using associated detection technique；
3. long (5-8) using the service life that associated detection technique can extend detector.
The foregoing is merely illustrative of the preferred embodiments of the present invention, is not intended to limit the invention, it is noted that all
Made any modifications, equivalent replacements, and improvements etc. within the spirit and principles in the present invention should be included in guarantor of the invention
Within the scope of shield.
Claims (8)
1. the method for dual sensor joint-detection volatile organic gases, it is characterised in that: by semiconductor sensor circuit and
Thermal conductivity gas sensor circuit detects volatile organic gases；
Semiconductor sensor circuit includes semiconductor transducer and semiconductor signal processing circuit；Thermal conductivity gas sensor circuit packet
Include thermal conductivity gas sensor and thermal conductivity sensor signal processing circuit；
Semiconductor sensor circuit and thermal conductivity gas sensor circuit are respectively connected to single-chip microcontroller.
2. the method for dual sensor joint-detection volatile organic gases according to claim 1, it is characterised in that: partly lead
Body sensor qualitative detection volatile organic gases.
3. the method for dual sensor joint-detection volatile organic gases according to claim 1, it is characterised in that: thermal conductivity
Gas sensor quantitative detection all gas.
4. the method for dual sensor joint-detection volatile organic gases according to claim 1, it is characterised in that: partly lead
Body sensor is only used as threshold decision, and thermal conductivity sensor is exported as final concentration, when containing volatile organic matter in environment,
Semiconductor transducer test side voltage can rise, when voltage is more than certain threshold value, starting thermal conductivity sensor voltage output, to turn
It is melted into the output of detector concentration.
5. the method for dual sensor joint-detection volatile organic gases according to claim 1, it is characterised in that: partly lead
Body sensor circuit includes resistance R1-R4, capacitor C1 and C2, semiconductor transducer.
6. the method for dual sensor joint-detection volatile organic gases according to claim 5, it is characterised in that: partly lead
No. 3 of body sensor connect 5V power supply with No. 4 pins；
No. 1 pin of semiconductor transducer is separately connected resistance R2-R4, and No. 2 pins of semiconductor transducer are separately connected resistance
R1 and resistance R2；
It is connected after resistance R1 and capacitor C1 connection with single-chip microcontroller；
Resistance R3 ground connection, resistance R4 form the end SHORT, the other end ground connection of capacitor C2 after connecting with capacitor C2.
7. the method for dual sensor joint-detection volatile organic gases according to claim 1, it is characterised in that: thermal conductivity
Gas sensor circuit includes resistance R5-R19, capacitor C3-C10, thermal conductivity gas sensor, amplifier U1 and U2.
8. the method for dual sensor joint-detection volatile organic gases according to claim 7, it is characterised in that:
No. 7 pins and No. 8 pin serial connections of thermal conductivity gas sensor, No. 4 pins and No. 5 pin strings of thermal conductivity gas sensor
Connection；
No. 1 pin of thermal conductivity gas sensor is separately connected resistance R6, R9 and R12, and No. 2 pins of thermal conductivity gas sensor connect
No. 3 pins on ground, thermal conductivity gas sensor are grounded by resistance R10, No. 6 pins ground connection of thermal conductivity gas sensor；
Resistance R6, R7, R5 and capacitor C3 and C4 link together, another termination 5V power supply of resistance R5, capacitor C3's and C4
The other end ground connection, resistance R7 and resistance R8 series connection, the other end of resistance R8 be separately connected resistance R9, resistance R13, resistance R10 with
And No. 2 pins of thermal conductivity gas sensor；
The inverting input terminal of amplifier U1 is separately connected resistance R11 and R14, resistance R11 ground connection, and resistance R14 is connected to amplifier
The output end of U1, the positive power source terminal of amplifier U1 are separately connected resistance R15 and capacitor C6, and resistance R15 connects 5v power supply, and capacitor C6 connects
Ground, the negative power end ground connection of amplifier U1；The non-inverting input terminal of amplifier U1 is separately connected resistance R12 and capacitor C5, capacitor C5
The other end be separately connected the non-inverting input terminal of resistance R13 and amplifier U2；
The non-inverting input terminal of amplifier U2 is grounded by capacitor C9, the negative voltage side ground connection of amplifier U2, the reverse phase of amplifier U2
Resistance R16 is set between input terminal and the output end of amplifier U1, and the inverting input terminal of amplifier U2 is also respectively connected with capacitor C7
The output end of amplifier U2 is connected to resistance R17, capacitor C7 and resistance R17, the positive voltage terminal of amplifier U2 is separately connected electricity
Hinder R18 and capacitor C8, resistance R18 connection 5v power supply, capacitor C8 ground connection；Amplifier U2's connect with resistance R19, resistance R19 with
Capacitor C10 is connected, capacitor C10 ground connection, wherein the end AD_Signal is drawn on the bus of resistance R19 and capacitor C10.
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| CN201811629606.6A CN109470745A (en) | 2018-12-28 | 2018-12-28 | The method of dual sensor joint-detection volatile organic gases |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110118860A (en) * | 2019-05-28 | 2019-08-13 | 成都安可信电子股份有限公司 | For detecting the dual sensor joint detector and method of fuel gas and steam |
| CN111830086A (en) * | 2020-05-07 | 2020-10-27 | 西安电子科技大学 | Preparation method of gas sensor based on polyaniline film surface modification |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104502550A (en) * | 2015-01-20 | 2015-04-08 | 成都海兰天澄科技有限公司 | Continuous online detection system for plurality of types of pollution gas |
| CN106153830A (en) * | 2016-08-11 | 2016-11-23 | 重庆大学 | Universal electric nasus system and detection method thereof |
| CN106802339A (en) * | 2017-01-19 | 2017-06-06 | 烟台睿创微纳技术股份有限公司 | A kind of array type MEMS gas sensors |
| CN108318926A (en) * | 2018-02-09 | 2018-07-24 | 李法利 | The Detection Circuit and method of rays safety detection apparatus |
| CN207851026U (en) * | 2018-01-31 | 2018-09-11 | 珠海市中科领航科技有限公司 | Systematic gas monitoring system |
-
2018
- 2018-12-28 CN CN201811629606.6A patent/CN109470745A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104502550A (en) * | 2015-01-20 | 2015-04-08 | 成都海兰天澄科技有限公司 | Continuous online detection system for plurality of types of pollution gas |
| CN106153830A (en) * | 2016-08-11 | 2016-11-23 | 重庆大学 | Universal electric nasus system and detection method thereof |
| CN106802339A (en) * | 2017-01-19 | 2017-06-06 | 烟台睿创微纳技术股份有限公司 | A kind of array type MEMS gas sensors |
| CN207851026U (en) * | 2018-01-31 | 2018-09-11 | 珠海市中科领航科技有限公司 | Systematic gas monitoring system |
| CN108318926A (en) * | 2018-02-09 | 2018-07-24 | 李法利 | The Detection Circuit and method of rays safety detection apparatus |
Non-Patent Citations (4)
| Title |
|---|
| 周云水: "《传感器应用易读通》", 31 August 2007, 中国电力出版社 * |
| 姜德谭 等: "《新编电子电路大全 第4卷 测量与传感电路》", 31 January 2001, 中国计量出版社 * |
| 沈建国 等: "《电子线路基础实验 模拟 数字》", 31 July 2003, 华东师范大学出版社 * |
| 赵守忠 等: "《传感器技术及工程应用》", 31 August 2013, 中国铁道出版社 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110118860A (en) * | 2019-05-28 | 2019-08-13 | 成都安可信电子股份有限公司 | For detecting the dual sensor joint detector and method of fuel gas and steam |
| CN111830086A (en) * | 2020-05-07 | 2020-10-27 | 西安电子科技大学 | Preparation method of gas sensor based on polyaniline film surface modification |
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Application publication date: 20190315 |