CN204214746U - Dust concentration instrument - Google Patents
Dust concentration instrument Download PDFInfo
- Publication number
- CN204214746U CN204214746U CN201420635222.6U CN201420635222U CN204214746U CN 204214746 U CN204214746 U CN 204214746U CN 201420635222 U CN201420635222 U CN 201420635222U CN 204214746 U CN204214746 U CN 204214746U
- Authority
- CN
- China
- Prior art keywords
- operational amplifier
- signal
- input
- voltage signal
- resistance
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Landscapes
- Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)
Abstract
The utility model discloses a kind of dust concentration instrument, comprise the primary amplifier circuit for generation of voltage signal Vout1, the selectable gain operation amplifier circuit for generation of voltage signal Vout2 and for generation of voltage signal Vout3 and voltage signal Vout4 end follow circuit, and main control chip and supporting analog to digital conversion and D/A converting circuit.The utility model extract simultaneously feeler lever electric charge induction electromotive force formed voltage signal in direct current and AC compounent, main control chip is analyzed direct current and AC compounent simultaneously simultaneously, and form backfeed loop, the analog AC component that feedback signal is biased by DC component and band forms, can feed back direct current signal and AC signal simultaneously, more can accurately calculate the electric charge detected in feeler lever.Programmable-gain operation amplifier circuit is convenient in addition calibrates the electric charge that different dusts is formed, and makes this circuit can be applicable to the dust of various different structure.
Description
Technical field
The utility model belongs to powder concentration measurement technical field, is specifically related to a kind of instrument discharge dust concentration being carried out to on-line real-time measuremen.
Background technology
Dust concentration instrument, according to the difference of application, can be divided into environment dust instrument and pipeline dust instrument.
Environment dust instrument is for measuring dust or the particle concentration of open space.Can be widely used in every profession and trade to factory building, working environment, working space, office, exterior space etc. carries out the monitoring of online dust concentration in real time, and mine and the inferior special industrial dust concentration monitoring of coal mine.
Pipeline dust instrument can be used for monitoring all kinds of flue dust concentration Long-term change trend, the monitoring of stationary pollution source dust emission and solid powder course of conveying and burden control.Usually be installed on the downstream of filtrator, cyclone or similar devices, monitoring concentration of solid particles, Leakage prevention occurs, and provides early warning.Can power plant be widely used in, metallurgical, the field such as chemical industry and casting.
At present, dust concentration detector mainly contains the dust concentration On-line Measuring Method such as capacitance method, β rays method, light scattering method, optical absorption method, friction electrical method.The measuring principle of capacitance method is simple, but not linear relationship one to one between measurement capacitance and concentration, the measured value of electric capacity is subject to the impact of Entropy density deviation and variations in flow patterns, causes larger measuring error; Although β rays method is measured accurately, measurement of comparison after needing to sample to dust, is difficult to the on-line monitoring realizing dust concentration.Therefore, comparatively ripe at present mode adopts light scattering method, optical absorption method, friction electrical method to carry out dust concentration on-line monitoring.And the electrical method that rubs has following advantage relative to optical method: very little particle can be measured; Not affected by vibration; The color of dust does not affect measurement; Optical window is not had to need to keep clean.Therefore the research and development direction of dust at present concentration meter is become.
But what the dust concentration instrument based on friction electrical method adopted is exchange electrostatic induction principle, the induced charge due to dust granules mutual friction of motion, when dust charge electrical contact or near sensor electrode or crash sensor, induction electromotive force on electrode.Because its induction electromotive force is very faint, therefore very high requirement is proposed for the hardware circuit processed and software algorithm.
Therefore, can provide that a kind of dust accuracy of detection is high, low cost of manufacture, to use safely and the dust concentration detector of reliable operation excellence has technical matters to be solved at present again.
Utility model content
In order to solve the problem, it is reliable that the purpose of this utility model is to provide a kind of circuit structure, and accuracy of detection is high, non-maintaining dust concentration detector.
The utility model proposes following technical solution: a kind of dust concentration detector, comprise charge signal sensor, amplifying circuit and follower, the signal output part of charge signal sensor is connected with the signal input part Signal of elementary amplifying circuit, the output end voltage signal Vout1 of primary amplifier circuit is connected with selectable gain operation amplifier circuit input end, the output end voltage signal Vout2 of selectable gain operation amplifier circuit is connected with the input end of end follow circuit, the output terminal ac voltage signal Vout3 of end follow circuit is connected with analog to digital conversion circuit, the output terminal d. c. voltage signal Vout4 of end follow circuit is connected with analog to digital conversion circuit.
Described primary amplifier circuit comprises ultralow input current operational amplifier U1, resistance R1, R2, R3, R4 and filter capacitor C1, C2, C3, C4 forms, contact resistance R1 and electric capacity C1 between the signal input part Signal of current operational amplifier U1 and the negative input end of output end voltage signal Vout1, contact resistance R2 between signal input part Signal and current operational amplifier U1, contact resistance R3 between the positive input terminal of biasing voltage signal Vbias and current operational amplifier U1, the positive input terminal of current operational amplifier U1 is by resistance R4 ground connection, and by electric capacity C2 ground connection.Signal input part Signal is the induced electromotive force signal that triboelectric charge produces.Current operational amplifier U1 selects LMC6001, when choosing R3=R2, during R4=R1, and output voltage Vout1=Vbias-Signal.For the induced electromotive force signal will produced by triboelectric charge, realize ultralow current input signal and amplify, and increase bias voltage adjustment, export to next stage circuit.
Described selectable gain operation amplifier circuit comprises gain programmable operational amplifier U2, signal ASel is selected to be connected with gain programmable operational amplifier U2 current input terminal, output end voltage signal Vout1 from current operational amplifier U1 is connected with gain programmable operational amplifier U2 input cathode, two groups of simulating signal Vdac1 are connected with gain programmable operational amplifier U2 input anode with resistance R6, resistance R7 respectively through resistance R5 with Vdac2, biasing voltage signal Vbias, and resistance R5, R6, R7 form.Gain programmable operational amplifier U2 selects low noise gain programmable operational amplifier PGA205, digital signal ASel can select the gain of gain programmable operational amplifier U2, by carrying out the selection of gain size, select different dusts grain size to the proportionate relationship of electric charge.Form simulating signal Vdac1, Vdac2 by two groups of digital to analog converters simultaneously, wherein Vdac1 is DC feedback signal, Vdac2 is the AC regeneration signal of band bias voltage of simulation, by resistance R5, R6, R7 formed operational amplifier+end input, last output voltage:
Vout2＝G*[(R6*R7*Vdac1+R5*R7*Vdac2+R5*R6*Vbia)/(R5*R6+R5*R7+R6*R7)–Vout1]。
Vout2 is divided into two-way by two groups of followers by described end follower circuit, Vout2 first via signal is connected with operational amplifier U3 electrode input end by resistance R9, operational amplifier U3 negative input and output terminal contact resistance R9, operational amplifier U3 output terminal is successively through electric capacity C5, diode D1 is connected with the electrode input end of operational amplifier U4 with after resistance R12, operational amplifier U4 electrode input end input end is connected to ground by electric capacity C6, the negative input of operational amplifier U4 and output terminal contact resistance R11 and electric capacity C7 respectively, operational amplifier U4 output terminal is ac voltage signal Vout3, enter analog to digital conversion, for reading.Vout2 second road signal is connected with operational amplifier U5 input anode by resistance R12, operational amplifier U5 input cathode and output terminal contact resistance R18, operational amplifier U5 output terminal is connected with the input end of low-pass filter U6, the output terminal of low-pass filter U6 is d. c. voltage signal Vout4, enter analog to digital conversion, for reading.U3, U5, U4 choose the ambipolar high precision operating amplifier OP07 of low noise, non-chopper-zero-stabilized, and Main Function reduces output impedance.U6 chooses the high performance low-pass filter LTC1063 of high precision low noise, can extract the low-pass signal component in signal very accurately.
Signal is divided into DC component after filtering and AC compounent is sampled respectively into master chip, and master chip adds upper offset by DAC and forms feedback, can calibrate dust concentration by signal scaling.
The beneficial effects of the utility model: can be applicable to, in the smoke discharging pipe of the factory of the discharge such as power plant, cement mill dust flue gas, carry out on-line real-time measuremen to the dust concentration of discharge.The utility model due to extract simultaneously feeler lever electric charge induction electromotive force formed voltage signal in direct current and AC compounent, direct current and AC compounent are analyzed simultaneously simultaneously, and form backfeed loop, the analog AC component that feedback signal is biased by DC component and band forms, can feed back direct current signal and AC signal simultaneously, more can accurately calculate the electric charge detected in feeler lever.Programmable-gain operation amplifier circuit is convenient in addition calibrates the electric charge that different dusts is formed, and makes this circuit can be applicable to the dust of various different structure.
Accompanying drawing explanation
Fig. 1 is theory diagram of the present utility model
Fig. 2 is the electrical schematic diagram of the primary amplifier circuit shown in Fig. 1
Fig. 3 is the electrical schematic diagram of the selectable gain operation amplifier circuit shown in Fig. 1
Fig. 4 is the electrical schematic diagram of the end follow circuit shown in Fig. 1
Embodiment
A kind of dust concentration detector, see Fig. 1, comprise charge signal sensor, the primary amplifier circuit for generation of voltage signal Vout1, the selectable gain operation amplifier circuit for generation of voltage signal Vout2 and for generation of voltage signal Vout3 and Vout4 end follow circuit, and main control chip and supporting analog to digital conversion and D/A converting circuit.
The signal output part of charge signal sensor is connected with the signal input part Signal of elementary amplifying circuit, the output end voltage signal Vout1 of primary amplifier circuit is connected with selectable gain operation amplifier circuit input end, the output end voltage signal Vout2 of selectable gain operation amplifier circuit is connected with the input end of end follow circuit, the output terminal ac voltage signal Vout3 of end follow circuit is connected with analog to digital conversion circuit, by analog to digital conversion circuit conversion input main control chip, the output terminal d. c. voltage signal Vout4 of end follow circuit is connected with analog to digital conversion circuit, by analog to digital conversion circuit conversion input main control chip, main control chip passes through digital-to-analog conversion output offset voltage Vbias to primary amplifier circuit and selectable gain operation amplifier circuit simultaneously.
See Fig. 2, primary amplifier circuit comprises ultralow input current operational amplifier U1, resistance R1, R2, R3, R4 and filter capacitor C1, C2, C3, C4 forms, contact resistance R1 and electric capacity C1 between the signal input part Signal of current operational amplifier U1 and the negative input end of output end voltage signal Vout1, contact resistance R2 between signal input part Signal and current operational amplifier U1, from contact resistance R3 between the biasing voltage signal Vbias of main control chip and the positive input terminal of current operational amplifier U1, the positive input terminal of current operational amplifier U1 is by resistance R4 ground connection, and by electric capacity C2 ground connection.Signal input part Signal is the induced electromotive force signal that triboelectric charge produces.Current operational amplifier U1 selects LMC6001, when choosing R3=R2, during R4=R1, and output voltage Vout1=Vbias-Signal.For the induced electromotive force signal will produced by triboelectric charge, realize ultralow current input signal and amplify, and increase bias voltage adjustment, export to next stage circuit.
See Fig. 3, selectable gain operation amplifier circuit comprises gain programmable operational amplifier U2, selection signal ASel from main control chip is connected with gain programmable operational amplifier U2 current input terminal, output end voltage signal Vout1 from current operational amplifier U1 is connected with gain programmable operational amplifier U2 input cathode, from two groups of simulating signal Vdac1 and Vdac2 of main control chip, biasing voltage signal Vbias is respectively through resistance R5 and resistance R6, resistance R7 is connected with gain programmable operational amplifier U2 input anode, resistance R5, R6, R7 forms.Gain programmable operational amplifier U2 selects low noise gain programmable operational amplifier PGA205, the gain of gain programmable operational amplifier U2 can be selected from the digital signal ASel of main control chip transmission, carried out the selection of gain size by main control chip, select different dusts grain size to the proportionate relationship of electric charge.Main control chip forms simulating signal Vdac1, Vdac2 by two groups of digital to analog converters simultaneously, wherein Vdac1 is DC feedback signal, Vdac2 is the AC regeneration signal of band bias voltage of simulation, by resistance R5, R6, R7 formed operational amplifier+end input, last output voltage:
Vout2=G* [(R6*R7*Vdac1+R5*R7*Vdac2+R5*R6*Vbia)/(R5*R6+R5*R7+R6*R7) – Vout1] (" wherein G is able to programme by main control chip signal Asel ").
See Fig. 4, Vout2 is divided into two-way by two groups of followers by end follower circuit, Vout2 first via signal is connected with operational amplifier U3 electrode input end by resistance R9, operational amplifier U3 negative input and output terminal contact resistance R9, operational amplifier U3 output terminal is successively through electric capacity C5, diode D1 is connected with the electrode input end of operational amplifier U4 with after resistance R12, operational amplifier U4 electrode input end input end is connected to ground by electric capacity C6, the negative input of operational amplifier U4 and output terminal contact resistance R11 and electric capacity C7 respectively, operational amplifier U4 output terminal is ac voltage signal Vout3, enter analog to digital conversion, read for main control chip.Vout2 second road signal is connected with operational amplifier U5 input anode by resistance R12, operational amplifier U5 input cathode and output terminal contact resistance R18, operational amplifier U5 output terminal is connected with the input end of low-pass filter U6, the output terminal of low-pass filter U6 is d. c. voltage signal Vout4, enter analog to digital conversion, read for main control chip.U3, U5, U4 choose the ambipolar high precision operating amplifier OP07 of low noise, non-chopper-zero-stabilized, and Main Function reduces output impedance.U6 chooses the high performance low-pass filter LTC1063 of high precision low noise, can extract the low-pass signal component in signal very accurately.
Signal is divided into DC component after filtering and AC compounent is sampled respectively into master chip, and master chip adds upper offset by DAC and forms feedback, can calibrate dust concentration by signal scaling.
Claims (4)
1. a dust concentration instrument, comprise charge signal sensor, primary amplifier circuit and end follower circuit, it is characterized in that, primary amplifier circuit comprises ultralow input current operational amplifier U1, contact resistance R1 and electric capacity C1 between the signal input part Signal of current operational amplifier U1 and the negative input end of output end voltage signal Vout1, contact resistance R2 between signal input part Signal and current operational amplifier U1, contact resistance R3 between the positive input terminal of biasing voltage signal Vbias and current operational amplifier U1, the positive input terminal of current operational amplifier U1 is by resistance R4 ground connection, and by electric capacity C2 ground connection, selectable gain operation amplifier circuit comprises gain programmable operational amplifier U2, select signal ASel to be connected with gain programmable operational amplifier U2 current input terminal, the output end voltage signal Vout1 from current operational amplifier U1 is connected with gain programmable operational amplifier U2 input cathode, two groups of simulating signal Vdac1 are connected with gain programmable operational amplifier U2 input anode with resistance R6, resistance R7 respectively through resistance R5 with Vdac2, biasing voltage signal Vbias, Vout2 is divided into two-way by two groups of followers by end follower circuit, Vout2 first via signal is connected with operational amplifier U3 electrode input end by resistance R9, operational amplifier U3 negative input and output terminal contact resistance R9, operational amplifier U3 output terminal is successively through electric capacity C5, diode D1 is connected with the electrode input end of operational amplifier U4 with after resistance R12, operational amplifier U4 electrode input end input end is connected to ground by electric capacity C6, the negative input of operational amplifier U4 and output terminal contact resistance R11 and electric capacity C7 respectively, operational amplifier U4 output terminal is ac voltage signal Vout3, Vout2 second road signal is connected with operational amplifier U5 input anode by resistance R12, operational amplifier U5 input cathode and output terminal contact resistance R18, operational amplifier U5 output terminal is connected with the input end of low-pass filter U6, and the output terminal of low-pass filter U6 is d. c. voltage signal Vout4.
2. dust concentration instrument according to claim 1, is characterized in that, current operational amplifier U1 selects LMC6001.
3. dust concentration instrument according to claim 1, is characterized in that, gain programmable operational amplifier U2 selects low noise gain programmable operational amplifier PGA205.
4. dust concentration instrument according to claim 1, is characterized in that, operational amplifier U3, U5, U4 choose low noise, ambipolar high precision operating amplifier OP07, the U6 of non-chopper-zero-stabilized choose the high performance low-pass filter LTC1063 of high precision low noise.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420635222.6U CN204214746U (en) | 2014-10-29 | 2014-10-29 | Dust concentration instrument |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420635222.6U CN204214746U (en) | 2014-10-29 | 2014-10-29 | Dust concentration instrument |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN204214746U true CN204214746U (en) | 2015-03-18 |
Family
ID=52983411
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201420635222.6U Active CN204214746U (en) | 2014-10-29 | 2014-10-29 | Dust concentration instrument |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN204214746U (en) |
-
2014
- 2014-10-29 CN CN201420635222.6U patent/CN204214746U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Park et al. | Emission and speciation of mercury from various combustion sources | |
| CN101706563B (en) | Digital calibration system of partial discharge test equipment | |
| CN204694288U (en) | A kind of gas-solid diphasic stream parameter measurement mechanism | |
| CN100460831C (en) | Method and device for detecting micro-charge type online dust and detector pollution | |
| CN105527255A (en) | On-line monitoring system of coal characteristics of as-fired coal | |
| CN202582596U (en) | System for integrally measuring air quantity, concentration, and granularity | |
| Qi et al. | Influence of SO3 in flue gas on electrostatic precipitability of high-alumina coal fly ash from a power plant in China | |
| Davidsson et al. | A surface ionization instrument for on-line measurements of alkali metal components in combustion: Instrument description and applications | |
| Sun et al. | On-line nonintrusive detection of wood pellets in pneumatic conveying pipelines using vibration and acoustic sensors | |
| CN101907600B (en) | Device for measuring mine dust concentration based on differential principle | |
| CN104297120A (en) | Dust concentration meter | |
| CN105353398A (en) | System and method for on-line measurement of radon and thoron, and daughter concentration therefor | |
| CN101975733A (en) | Dust detection system and dust detection circuit | |
| CN204214746U (en) | Dust concentration instrument | |
| CN102095741A (en) | Method for detecting coal quality composition on conveying belt and device thereof | |
| CN104267056A (en) | X-ray fluorescence tester for testing heavy metal pollution of soil | |
| CN104034850A (en) | Device for evaluating property of oxidizing agent and adsorbent of gaseous elemental mercury | |
| CN103558267B (en) | A kind of dust concentration on-line detecting system based on capacitance measurement technique | |
| CN203705369U (en) | Multi-channel pulse amplitude analyzer of liquid security detection instrument | |
| CN106093837A (en) | A kind of assess digitalized electrical energy meter method of measuring accuracy under complex working condition | |
| CN107389972B (en) | Analyzer for on-line measuring boiler pipeline air-powder flow parameter | |
| CN205861507U (en) | Environmental monitoring dust granules system | |
| KR102236964B1 (en) | Log Count Rate Device for Low Frequency Band Output Signal Inspection | |
| CN201681091U (en) | Arced electrostatic sensor array measuring device for granule velocity distribution | |
| CN212082483U (en) | High-precision hydrogen flow detection circuit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |