CN206649008U - Gas concentration measuring apparatus based on differential type collection - Google Patents
Gas concentration measuring apparatus based on differential type collection Download PDFInfo
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- CN206649008U CN206649008U CN201720084220.6U CN201720084220U CN206649008U CN 206649008 U CN206649008 U CN 206649008U CN 201720084220 U CN201720084220 U CN 201720084220U CN 206649008 U CN206649008 U CN 206649008U
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- operational amplifier
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- gas concentration
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Abstract
The gas concentration measuring apparatus that the utility model is gathered based on differential type, including the probe for monitoring gas concentration and environment temperature, for being nursed one's health and being amplified the signal of gas sensor, while complete the power converter cells of temperature compensation signal conditioning all the way, the computer unit that gas concentration measurement data handle and show in real time, also differential type data acquisition and the data acquisition transmitted and usb communication unit are realized using difference A/D converter, (+) input of input difference formula A/D converter after the signal of gas sensor is nursed one's health and amplified, () input of input difference formula A/D converter after temperature compensation signal conditioning, form Differential Input.This patent realizes difference collection, the amplification to gas sensor measurement data, suppression common mode noise, the temperature-compensating of gas sensor is realized again, effectively reduces measurement noise, sensitiveness of the measurement apparatus to environment temperature is reduced, improves the measurement accuracy of gas sensor.
Description
Technical field
The utility model belongs to gas concentration measurement technical field, and in particular to a kind of gas based on differential type collection is dense
Spend measurement apparatus.
Background technology
Gas concentration measuring apparatus, generally include gas sensor (probe), power converter cells, data acquisition unit and meter
Four parts of calculation machine software processing elements.Being achieved in that for measurement apparatus amplifies gas sensor output by converter
Afterwards, analog signal is sent directly into the analog input end of A/D converter, and the ground of the ground of signal end and A/D converter connects together,
The collection of sensor signal is realized by single-ended A/D converter.The numeral letter that data acquisition unit obtains after A/D is changed
Number it is controlled and transmits, is sent into software processing unit, realizes the display and processing of gas concentration data.
In above-mentioned conventional art, for the method for traditional single-ended A/D converter collection gas sensor signal, sensor
Signal ground and the ground wire of A/D converter connect together.When the line between probe and power converter cells is longer, in gas sensing
Easily it is interfered on the analog signal line of device, causes the signal noise of data acquisition unit output end larger, for low concentration
Gasmetry for, signal can be submerged in noise substantially, and signal to noise ratio is very low, be unfavorable for light concentration gas accurate measurement and
Differentiate.
Utility model content
The purpose of this utility model is that to solve the above problems and provides a kind of gas based on differential type collection
Apparatus for measuring concentration.
The utility model is achieved through the following technical solutions above-mentioned purpose：
Based on the gas concentration measuring apparatus of differential type collection, including for monitoring the spy of gas concentration and environment temperature
Head, for being nursed one's health and being amplified the signal of gas sensor, while complete all the way temperature compensation signal conditioning change
Exchange unit, the computer unit for by gas concentration measurement data handle and show in real time, also turn using difference A/D
Parallel operation realizes differential type data acquisition and the data acquisition transmitted and usb communication unit, probe, power converter cells, data acquisition
And the data-signal of usb communication unit and computer unit transmits connection successively；The signal of gas sensor is nursed one's health and put
(+) input of input difference formula A/D converter after big, (-) of input difference formula A/D converter after temperature compensation signal conditioning
Input, form Differential Input.
Specifically, data acquisition and usb communication unit also include FPGA main control chips, the gas sensing for that will get
Usb communication chip that device signal is converted to the USB format data of standard and carried out data transmission, pass through USB cable and realize and meter
The Type B USB socket of the standard of calculation machine unit connection, the I/O mouths of FPGA the main control chips control with A/D converter and data respectively
The control of output port and usb communication chip and data-in port connect, the data-out port and standard of usb communication chip
The FPDP connection of Type B USB socket, USB cable realize Type B USB socket and the connection of computer of standard.
Specifically, probe includes being used for the gas sensor for monitoring gas concentration and the temperature sensitive electricity for environment temperature monitoring
Resistance；Power converter cells include Conditioning Circuits of Sensor and thermo-sensitive resistor modulate circuit；The signal output part and biography of gas sensor
The signal input part connection of sensor modulate circuit, the signal output part of thermo-sensitive resistor input with the signal of thermo-sensitive resistor modulate circuit
End connection, the signal output part of Conditioning Circuits of Sensor are connected with (+) input of differential type A/D converter, and thermo-sensitive resistor is adjusted
The signal output part of reason circuit is connected with (-) input of differential type A/D converter.
Preferably, differential type A/D converter model is ADS1118.
Preferably, usb communication chip model is FT245.
Specifically, Conditioning Circuits of Sensor is included by operational amplifier U1A, the first electric capacity, first resistor and second resistance
The in-phase amplifier of composition, the low-pass first order filter being made up of 3rd resistor and the second electric capacity and by operational amplifier U1B structures
Into penetrate a grade follower, the output signal U i access operational amplifiers U1A of gas sensor normal phase input end, operational amplifier
The first end of U1A the inverting input first end with first resistor, the first end of second resistance and the first electric capacity respectively is connected,
The second end ground connection of first resistor, the second end of the first electric capacity the second end with second resistance, the first end of 3rd resistor respectively
Connected with operational amplifier U1A output end, the second end of 3rd resistor first end and operation amplifier with the second electric capacity respectively
Device U1B in-phase input end connection, the second end ground connection of the second electric capacity, operational amplifier U1B inverting input and computing are put
Output sensor signal Um after big device U1B output end connection.
Preferably, operational amplifier U1A and operational amplifier U1B model are ADA4077-2.
Specifically, thermo-sensitive resistor modulate circuit is included by operational amplifier U1C, the 3rd electric capacity, the 8th resistance and the 9th electricity
Hinder the in-phase amplifier formed, the low-pass first order filter being made up of the tenth resistance and the 4th electric capacity, by operational amplifier U1D structures
Into penetrate a grade follower, the constant-current source being made up of the 4th resistance, the 5th resistance, the 6th resistance, the 7th resistance and thermo-sensitive resistor electricity
Road, 5V voltages access the first end of the 4th resistance, and the second end of the 4th resistance is connected with the first end of the 5th resistance, the 5th resistance
The second end be connected respectively with operational amplifier U1C normal phase input end and the first end of the 6th resistance, the second of the 6th resistance
End is connected with the first end of thermo-sensitive resistor, and the second end of thermo-sensitive resistor is connected with the first end of the 7th resistance, and the of the 7th resistance
Two ends are grounded, operational amplifier U1C the inverting input first end with the 8th resistance, the first end of the 9th resistance and the respectively
The first end connection of three electric capacity, the second end ground connection of the 8th resistance, the second end of the 3rd electric capacity respectively with the 9th resistance second
End, the first end of the tenth resistance connect with operational amplifier U1C output end, the second end of the tenth resistance respectively with the 4th electric capacity
First end connected with operational amplifier U1D in-phase input end, the second end of the 4th electric capacity ground connection, operational amplifier U1D's
Output temperature signal Ut after inverting input connects with operational amplifier U1D output end.
Preferably, operational amplifier U1C and operational amplifier U1D model are ADA4077-2.
The beneficial effects of the utility model are：
The utility model possesses advantages below：
(1) difference acquisition mode is used, realizes the gas sensor signal measurement under high s/n ratio, system is effectively reduced and surveys
The noise figure of amount, it ensure that higher measuring accuracy requirement.
(2) (-) input of hardware temperatures thermal compensation signal as differential type A/D converter is used, effectively reduces environment
Influence of the temperature to sensor signal, reduce sensitiveness of the measurement apparatus to temperature.
(3) by the way of being gathered based on difference, temperature-compensating is completed, differential amplification, collection is realized again, suppresses altogether
Mode noise, the high-acruracy survey of gas concentration is realized, the relatively common single-ended drainage pattern of the program, hardware is reduced and realizes rule
Mould, there is application prospect.
Brief description of the drawings
Fig. 1 is structured flowchart of the present utility model；
Fig. 2 is data acquisition and usb communication cellular construction schematic diagram in the utility model；
Fig. 3 is the circuit diagram of Conditioning Circuits of Sensor in the utility model；
Fig. 4 is the circuit diagram of thermo-sensitive resistor modulate circuit in the utility model.
In figure：101st, pop one's head in；102nd, power converter cells；103rd, data acquisition and usb communication unit；104th, computer list
Member；301st, differential type A/D converter；302nd, FPGA main control chips；303rd, usb communication chip；304th, the Type B USB socket of standard.
Embodiment
The utility model is described in further detail below in conjunction with the accompanying drawings：
As shown in Figure 1 and Figure 2, based on differential type collection gas concentration measuring apparatus, including for monitor gas concentration and
The probe 101 of environment temperature, for being nursed one's health and being amplified the signal of gas sensor, while complete all the way temperature mend
Repay the power converter cells 102 of signal condition, the computer unit for by gas concentration measurement data handle and show in real time
104, also realize differential type data acquisition and the data acquisition transmitted and usb communication unit using difference A/D converter
103, probe 101, power converter cells 102, data acquisition and the data-signal of usb communication unit 103 and computer unit 104 according to
Secondary transmission connection；(+) input of input difference formula A/D converter 301 after the signal of gas sensor is nursed one's health and amplified,
(-) input of input difference formula A/D converter 301, forms Differential Input after temperature compensation signal conditioning.
Differential type A/D converter 301 possesses the function to differential signal programmable automation controller in the utility model, can incite somebody to action
Gas sensor output signal carries out differential amplification with temperature compensation signal, A/D is changed, and obtains corresponding data signal.
Data acquisition and usb communication unit 103 also include FPGA main control chips 302, the gas sensing for that will get
Usb communication chip 303 that device signal is converted to the USB format data of standard and carried out data transmission, by USB cable realize with
The Type B USB socket 304 for the standard that computer unit 104 connects, the I/O mouths of FPGA main control chips 302 respectively with A/D converter
301 control and the control of data-out port and usb communication chip 303 and data-in port connect, usb communication chip
303 data-out port is connected with the FPDP of standard Type B USB socket 304, and the Type B USB socket 304 of standard is with calculating
Machine unit 104 connects.
Computer unit 104 will transmit the data signal progress real time parsing come, pass through the concentration value that screen display measures.
Probe 101 includes being used for the gas sensor for monitoring gas concentration and the thermo-sensitive resistor for environment temperature monitoring；
Power converter cells 102 include Conditioning Circuits of Sensor and thermo-sensitive resistor modulate circuit；The signal output part and biography of gas sensor
The signal input part connection of sensor modulate circuit, the signal output part of thermo-sensitive resistor input with the signal of thermo-sensitive resistor modulate circuit
End connection, the signal output part of Conditioning Circuits of Sensor are connected with (+) input of differential type A/D converter 301, thermo-sensitive resistor
The signal output part of modulate circuit is connected with (-) input of differential type A/D converter 301.
Preferably, the model of differential type A/D converter 301 is ADS1118.
Preferably, the model of usb communication chip 303 is FT245.
As shown in figure 3, specifically, sensor modulate circuit is included by operational amplifier U1A, the first electric capacity C1, first resistor
The in-phase amplifier of R1 and second resistance R2 compositions, by 3rd resistor R3 and the second electric capacity C2 low-pass first order filter formed and
A grade follower, the output signal U i access operational amplifiers U1A of gas sensor positive are penetrated by what operational amplifier U1B was formed
Input, operational amplifier U1A inverting input respectively the first end with first resistor R1, second resistance R2 first end and
First electric capacity C1 first end connection, first resistor R1 the second end ground connection, the first electric capacity C1 the second end are electric with second respectively
Hinder R2 the second end, 3rd resistor R3 first end connects with operational amplifier U1A output end, 3rd resistor R3 the second end
It is connected respectively with the second electric capacity C2 first end and operational amplifier U1B in-phase input end, the second electric capacity C2 the second termination
Ground, output sensor signal Um after operational amplifier U1B inverting input connects with operational amplifier U1B output end.The
The small-signal of gas sensor is amplified by the in-phase amplifier of one resistance R1 and second resistance R2 compositions；By 3rd resistor
The low-pass first order filter of R3 and the second electric capacity C2 compositions can filter out high-frequency noise, obtain the higher sensor signal of signal to noise ratio.
Preferably, operational amplifier U1A and operational amplifier U1B model are ADA4077-2.
As shown in figure 4, specifically, thermo-sensitive resistor modulate circuit is included by operational amplifier U1C, the 3rd electric capacity C3, the 8th
The in-phase amplifier of resistance R8 and the 9th resistance R9 compositions, the first-order low-pass being made up of the tenth resistance R10 and the 4th electric capacity C4
Ripple device, by what operational amplifier U1D was formed penetrate a grade follower, by the 4th resistance R4, the 5th resistance R5, the 6th resistance R6, the 7th
The constant-current source circuit that resistance R7 and thermo-sensitive resistor RT is formed, 5V voltages access the 4th resistance R4 first end, the 4th resistance R4's
Second end is connected with the 5th resistance R5 first end, and the 5th resistance R5 the second end is defeated with operational amplifier U1C positive respectively
Enter end to connect with the 6th resistance R6 first end, the 6th resistance R6 the second end is connected with thermo-sensitive resistor RT first end, temperature sensitive
Resistance RT the second end is connected with the 7th resistance R7 first end, the 7th resistance R7 the second end ground connection, operational amplifier U1C's
Inverting input respectively the first end with the 8th resistance R8, the 9th resistance R9 first end and the 3rd electric capacity C3 first end connect
Connect, the 8th resistance R8 the second end ground connection, the 3rd electric capacity C3 the second end the second end with the 9th resistance R9, the tenth resistance respectively
R10 first end connects with operational amplifier U1C output end, and the tenth resistance R10 the second end is respectively with the 4th electric capacity C4's
First end connects with operational amplifier U1D in-phase input end, the 4th electric capacity C4 the second end ground connection, operational amplifier U1D's
Output temperature signal Ut after inverting input connects with operational amplifier U1D output end.The access of 5V voltages is constant-current source circuit
Power supply；4th resistance R4, the 5th resistance R5, the 6th resistance R6 and the 7th resistance R7 form resistor network and provided to thermo-sensitive resistor RT
Suitable operating current simultaneously obtains voltage signal necessarily bias, comprising temperature information, and the signal is sent into operational amplifier U1C
(+) end, the in-phase amplifier formed by the 8th resistance R8 and the 9th resistance R9, temperature signal is amplified, then passes through
The low-pass first order filter that tenth resistance R10 and the 4th electric capacity C4 is formed, obtains the higher temperature signal of signal to noise ratio, and signal passes through
After what operational amplifier U1D was formed penetrates grade follower, that is, the temperature signal Ut of final output is obtained, the signal is sent into A/D conversions
(-) input of device 301.
Preferably, operational amplifier U1C and operational amplifier U1D model are ADA4077-2.
This patent uses the gas concentration measuring method based on differential type collection, devises a kind of measurement apparatus, that is, realizes
Difference collection, amplification to gas sensor measurement data, suppression common mode noise, the temperature for again realizing gas sensor are mended
Repay.The differential type acquisition mode effectively reduces measurement noise, reduces sensitiveness of the measurement apparatus to environment temperature, improves
The measurement accuracy of gas sensor.
General principle, principal character and advantage of the present utility model has been shown and described above.The technical staff of the industry
It should be appreciated that the utility model is not restricted to the described embodiments, the simply explanation described in above-described embodiment and specification is originally
The principle of utility model, on the premise of the spirit and scope of the utility model is not departed from, the utility model also has various change
And improvement, these changes and improvements are both fallen within claimed the scope of the utility model.The utility model requires protection scope
Defined by appended claims and its effect thing.
Claims (9)
1. based on differential type collection gas concentration measuring apparatus, including for monitor gas concentration and environment temperature probe,
For being nursed one's health and being amplified the signal of gas sensor, while completing the converter of temperature compensation signal conditioning all the way
Unit, the computer unit for by gas concentration measurement data handle and show in real time, it is characterised in that：Also using difference
A/D converter is divided to realize differential type data acquisition and the data acquisition transmitted and usb communication unit, probe, power converter cells, number
Connection is transmitted successively according to collection and the data-signal of usb communication unit and computer unit；The signal of gas sensor is adjusted
(+) input of input difference formula A/D converter after reason and amplification, input difference formula A/D is changed after temperature compensation signal conditioning
(-) input of device, form Differential Input.
2. the gas concentration measuring apparatus according to claim 1 based on differential type collection, it is characterised in that：Data acquisition and
Usb communication unit also includes FPGA main control chips, the USB format for the gas sensor signal got to be converted to standard
Data and usb communication chip, the Type B USB for the standard being connected by USB cable realization with computer unit carried out data transmission
Socket, the control of the I/O mouths of FPGA the main control chips control with A/D converter and data-out port and usb communication chip respectively
System and data-in port connection, the data-out port of usb communication chip are connected with the FPDP of standard Type B USB socket,
USB cable realizes Type B USB socket and the connection of computer of standard.
3. the gas concentration measuring apparatus according to claim 1 based on differential type collection, it is characterised in that：Probe includes being used for
Monitor the gas sensor of gas concentration and the thermo-sensitive resistor for environment temperature monitoring；Power converter cells are nursed one's health including sensor
Circuit and thermo-sensitive resistor modulate circuit；The signal output part of gas sensor and the signal input part of Conditioning Circuits of Sensor connect
Connect, the signal output part of thermo-sensitive resistor is connected with the signal input part of thermo-sensitive resistor modulate circuit, the letter of Conditioning Circuits of Sensor
Number output end is connected with (+) input of differential type A/D converter, the signal output part and differential type of thermo-sensitive resistor modulate circuit
(-) input connection of A/D converter.
4. the gas concentration measuring apparatus according to claim 1 based on differential type collection, it is characterised in that：Differential type A/D turns
Parallel operation model is ADS1118.
5. the gas concentration measuring apparatus according to claim 2 based on differential type collection, it is characterised in that：Usb communication chip
Model is FT245.
6. the gas concentration measuring apparatus according to claim 3 based on differential type collection, it is characterised in that：Sensor conditioning electricity
Road include be made up of operational amplifier U1A, the first electric capacity, first resistor and second resistance in-phase amplifier, by 3rd resistor
A grade follower is penetrated with the low-pass first order filter of the second electric capacity composition and by what operational amplifier U1B was formed, gas sensor
Output signal U i access operational amplifiers U1A normal phase input end, operational amplifier U1A inverting input are electric with first respectively
The first end of resistance, the first end of second resistance connect with the first end of the first electric capacity, the second end ground connection of first resistor, the first electricity
The output end at the second end the second end with second resistance, the first end of 3rd resistor and operational amplifier U1A respectively that hold is connected,
Second end of 3rd resistor is connected with the first end of the second electric capacity and operational amplifier U1B in-phase input end respectively, the second electricity
The the second end ground connection held, after operational amplifier U1B inverting input connect with operational amplifier U1B output end output sense
Device signal Um.
7. the gas concentration measuring apparatus according to claim 6 based on differential type collection, it is characterised in that：Operational amplifier
U1A and operational amplifier U1B model are ADA4077-2.
8. the gas concentration measuring apparatus according to claim 3 based on differential type collection, it is characterised in that：Thermo-sensitive resistor is nursed one's health
Circuit include be made up of operational amplifier U1C, the 3rd electric capacity, the 8th resistance and the 9th resistance in-phase amplifier, by the tenth electricity
Resistance and the 4th electric capacity composition low-pass first order filter, by operational amplifier U1D form penetrate a grade follower, by the 4th resistance,
The constant-current source circuit that 5th resistance, the 6th resistance, the 7th resistance and thermo-sensitive resistor are formed, 5V voltages access the first of the 4th resistance
End, the second end of the 4th resistance is connected with the first end of the 5th resistance, the second end of the 5th resistance respectively with operational amplifier U1C
Normal phase input end and the 6th resistance first end connection, the first end of the second end of the 6th resistance and thermo-sensitive resistor connects, temperature
Second end of quick resistance is connected with the first end of the 7th resistance, and the second end ground connection of the 7th resistance, operational amplifier U1C's is anti-phase
Input is connected with the first end, the first end of the 9th resistance and the first end of the 3rd electric capacity of the 8th resistance respectively, the 8th resistance
The second end ground connection, the second end with the 9th resistance, the first end of the tenth resistance and computing are put respectively at the second end of the 3rd electric capacity
Big device U1C output end connection, the second end of the tenth resistance are same with the first end of the 4th electric capacity and operational amplifier U1D respectively
Phase input connects, the second end of the 4th electric capacity ground connection, operational amplifier U1D inverting input and operational amplifier U1D's
Output temperature signal Ut after output end connection.
9. the gas concentration measuring apparatus according to claim 8 based on differential type collection, it is characterised in that：Operational amplifier
U1C and operational amplifier U1D model are ADA4077-2.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201720084220.6U CN206649008U (en) | 2017-01-20 | 2017-01-20 | Gas concentration measuring apparatus based on differential type collection |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201720084220.6U CN206649008U (en) | 2017-01-20 | 2017-01-20 | Gas concentration measuring apparatus based on differential type collection |
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| Publication Number | Publication Date |
|---|---|
| CN206649008U true CN206649008U (en) | 2017-11-17 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201720084220.6U Expired - Fee Related CN206649008U (en) | 2017-01-20 | 2017-01-20 | Gas concentration measuring apparatus based on differential type collection |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106645590A (en) * | 2017-01-20 | 2017-05-10 | 中国工程物理研究院总体工程研究所 | Gas concentration measurement device based on differential acquisition |
| CN108681515A (en) * | 2018-07-20 | 2018-10-19 | 南京林业大学 | A kind of USB self-powereds chromatographic signal sampling card |
| CN113533448A (en) * | 2021-06-21 | 2021-10-22 | 北京机械设备研究所 | Gas sensor testing system, testing method and upper computer |
| WO2023206663A1 (en) * | 2022-04-28 | 2023-11-02 | 瑞声声学科技(深圳)有限公司 | Gas sensor |
-
2017
- 2017-01-20 CN CN201720084220.6U patent/CN206649008U/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106645590A (en) * | 2017-01-20 | 2017-05-10 | 中国工程物理研究院总体工程研究所 | Gas concentration measurement device based on differential acquisition |
| CN108681515A (en) * | 2018-07-20 | 2018-10-19 | 南京林业大学 | A kind of USB self-powereds chromatographic signal sampling card |
| CN113533448A (en) * | 2021-06-21 | 2021-10-22 | 北京机械设备研究所 | Gas sensor testing system, testing method and upper computer |
| WO2023206663A1 (en) * | 2022-04-28 | 2023-11-02 | 瑞声声学科技(深圳)有限公司 | Gas sensor |
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