CN103868877A - Infrared gas sensor and detecting method thereof - Google Patents

Infrared gas sensor and detecting method thereof Download PDF

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CN103868877A
CN103868877A CN201410094249.3A CN201410094249A CN103868877A CN 103868877 A CN103868877 A CN 103868877A CN 201410094249 A CN201410094249 A CN 201410094249A CN 103868877 A CN103868877 A CN 103868877A
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infrared
light source
resistance
gas
temperature
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CN103868877B (en
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刘永平
刘丁鑫
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Abstract

The invention provides an infrared gas sensor and a detecting method thereof in order to overcome the defects of a traditional mining infrared gas sensor. The sensor comprises a shell, an inner barrel, a circuit module, a light source, an infrared detector, a temperature sensor, a filter membrane, a metal mesh and a vent plate, wherein the light source is used for periodically radiating light waves after being modulated, the light waves irradiate the infrared detector after being absorbed by gas to be detected, and an electric signal modulated to have the same period with the light source is extracted through filtration and amplification. The infrared gas sensor is used for detecting the concentration of the gas to be detected under a measuring mode and calibrating equipment under a calibration mode. The infrared gas sensor has the beneficial effects of stably and reliably operating in a severe environment for a long term and having anti-explosion performance; a breathable air chamber is formed under the heating of the light waves periodically radiated by the light source, and is integrated with an optical system, so that the concentration of a plurality of gases can be simultaneously detected; in addition, the measuring and calibrating methods are simple and reliable.

Description

A kind of infrared gas sensor and detection method
Technical field
The invention belongs to explosion-proof detection technique field, be specifically related to the gas detection technology under coal mine, relate in particular to multi-component infrared gas sensor and detection method.
Background technology
Infrared gas sensor, is to utilize tested gas the infrared radiation of specific wavelength to be had to the principle of absorption, carrys out the concentration of mensurated gas composition according to the variation of some certain wave strong point absorption peak on various gaseous spectrum curves.
Adopt the multicomponent gas sensor of infrared technique, make up the deficiency of colliery detecting instrument, improve the performance of detecting instrument, for mine safety provides more effective detection means and equipment, to improving the safety in production in colliery, ensure that national wealth and personnel's life security have extremely important realistic meaning.But, existing infrared gas sensor can not be suitable for using under explosive atmosphere under coal mine, rugged surroundings, temperature, steam, dust, corrosive gas, flammable explosive gas cause damage to sensor, make its hydraulic performance decline, and concrete manifestation is summarized as following several aspect:
1, existing sensor adopts traditional infrared gas detection means, does not take into full account the impact of rugged surroundings on sensor under coal mine, adopts detection method and temperature compensation, can not ensure stability and the reliability of sensor long-term work;
2, explosion-proof, dustproof, damp proof, the anticorrosive property of existing sensor, anti-tampering poor performance, affect the safe handling of sensor under rugged surroundings and the accuracy of measurement;
3, existing sensor air chamber structure and optical system complexity, therefore, manufacturing process complexity, cost are high, difficult in maintenance, are also difficult to realize the measurement to multicomponent gas;
4, existing sensor air chamber structure and detection method, is unfavorable for the abundant exchanging gas of air chamber and environment, causes measuring the response time long, and what gas in environment was detected is unreliable;
5, existing sensor generally only detects a kind of gas concentration;
6, existing sensor is only exported the electric signal that infrared eye transforms mostly, there is no follow-up signal processing;
7, existing sensor does not provide good transducer calibration and measuring method.
For this reason, a large amount of scientific research institutions and industrial enterprise conduct extensive research and technology exploration infrared gas sensor, but still have require further improvement, perfect place.Patent " a kind of non-dispersive infrared gas sensor " processing (CN201477043U) is simpler, but is difficult to realize the focusing of light path.Patent " double light source double sensitive element infra-red multiple gas detection sensor " (CN101105449) provides one two light source sensitive element infrared gas detection sensors, its light channel structure complexity, need focusing mirror, and the manufacture of air chamber is comparatively complicated, poor practicability, this device is without self-inspection and transfer function, being limited in scope of use.It is to introduce the method for a kind of reception and registration from the control information of infrared gas sensor that patent " has the infrared gas sensor of communication facilities and pass on the method from the control information of infrared gas sensor " (CN1886654A), be mainly the infrared energy for the infrared energy source in sensor outer housing, device one-piece construction and software approach do not proposed to integrated optimizing design scheme.
Summary of the invention
For the existing above-mentioned deficiency of existing infrared gas sensor, the invention provides a kind of infrared gas sensor and detection method, structure and detection method that it is concrete are respectively:
A kind of infrared gas sensor, comprises shell 1, Inner cylindrical shell 2 and circuit unit; Wherein, there is shell 1 in the outer cover of Inner cylindrical shell 2, be connected with circuit unit in the bottom of Inner cylindrical shell 2; In addition: described shell 1 is hollow cylinder, is provided with the step 11 of inside stretching, extension on the top of shell 1; Described step 11 ringwise; Be covered with one deck filtering membrane 12 at the main header casing of step 11; Be covered with layer of metal net 13 in the bottom of step 11, the bottom surface of wire netting 13 is connected with a vent board 14; Described vent board 14 is thin sheet of metal plate-like, is evenly equipped with a circle through hole 15 on vent board 14; By filtering membrane 12, wire netting 13 and vent board 14, the open top of shell 1 is covered;
Described Inner cylindrical shell 2, for the hollow cylinder of top sealing, is provided with outward extending annular edge 21 in the bottom of Inner cylindrical shell 2, be provided with a light inlet 22 on the sidewall of Inner cylindrical shell 2; In annular edge 21, be provided with an accurate tri-prismoid, described accurate tri-prismoid by reflecting plate 23, light barrier 24 and arc 26 around forming, wherein, reflecting plate 23 is connected with the corner angle limit of light barrier 24 connecting places and Inner cylindrical shell 2 sidewalls in light inlet 22 left sides, and one section of edge of the base of arc 26 and annular edge 21 coincides; Be provided with a through hole 25 near in the annular edge 21 of light barrier 24;
The bottom surface close contact of the end face of Inner cylindrical shell 2 and vent board 14; The annular edge 21 of Inner cylindrical shell 2 is joined with the inwall of shell 1; Annular edge 21 is filled with epoxy sealing with the junction of shell 1; The region that shell 1 and inner barrel 2 surround forms the air chamber 9 of this infrared gas sensor; Be that external environment gas is successively through the rear diffusion of through hole 15 of filtering membrane 12, wire netting 13 and vent board 14 air inlet chamber 9 of going forward side by side;
Described circuit unit comprises base plate 3, light source 4, infrared eye 5, temperature sensor 6 and signal processing circuit 7; Described base plate 3 is circular metal plate and isometric with the external diameter of annular edge 21; Base plate 3 is connected with the bottom surface of annular edge 21, by base plate 3, the opening of Inner cylindrical shell 2 belows is sealed;
Central authorities at base plate 3 end faces are provided with infrared eye 5; Be provided with temperature sensor 6 near on base plate 3 end faces of infrared eye 5; Light source 4 is arranged on air chamber 9 ends near light barrier 24 1 sides, and the bottom of light source 4 is connected with base plate 3 through through hole 25 is rear; Signal processing circuit 7 is placed on base plate 3, and by wire, infrared eye 5, temperature sensor 6 and light source 4 is connected with signal processing circuit 7 respectively;
The control end of described signal processing circuit 7 is connected with light source 4, to the voltage of light source 4 transport cycle; The signal input part of signal processing circuit 7 is connected with the signal output part of infrared eye 5 and temperature sensor 6 respectively;
Described light source 4 produces periodic radiation light-wave under the driving of periodic voltage; The periodicity radiation light-wave that light source 4 produces is radiated on infrared eye 5 through air chamber 9 multiple reflections and through light inlet 22; The periodicity radiation light-wave that light source 4 produces is on the one hand as the infrared radiation light wave that detects use, on the other hand the gas in air chamber 9 is periodically heated, impel the periodically dilation of gas in air chamber 9, carry out rapidly gas exchange thereby realize gas in air chamber 9 and the environmental gas of shell 1 outside, formed " respiratory air chamber ";
Infrared eye 5 is the periodicity radiation light-wave receiving, be converted into the electric signal of radiation light-wave same period after be passed to signal processing circuit 7; Temperature sensor 6 detects in real time near temperature infrared eye 5 and is passed to signal processing circuit 7, and the electric signal of infrared eye 5 being passed back for signal processing circuit 7 does temperature compensation.
Say further, the spectral range of the radiation light-wave that light source 4 sends is that visible ray is to infrared band.The preferred wavelength band of infrared radiation is 2～5 μ m, 8～12 μ m, 2～12 μ m and 2～20 μ m; Infrared eye 5 is made up of 2 to 16 infrared sensors, wherein 1 infrared sensor reception wavelength is the infrared radiation of 3.9 μ m, on the sensitive area of remaining infrared sensor, spike interference filter is all installed, receives the infrared radiation with the corresponding wavelength of spike interference filter; The radiation light-wave that light source 4 sends is after the multiple reflections of air chamber 9, and the hot spot direct irradiation of formation, on the whole sensitive area of infrared eye 5, does not add any converging or the optical device of light splitting in whole light path.
Say further, described signal processing circuit 7 is made up of arrowband bandpass filtering amplifying circuit 71, analog to digital conversion circuit 72, microprocessor 73, modulation of source driving circuit 74 and interface 75; The signal output part of each infrared sensor of infrared eye 5 is all connected with an arrowband bandpass filtering amplifying circuit 71; The signal output part of each arrowband bandpass filtering amplifying circuit 71 is connected with the multi-analog input end of analog to digital conversion circuit 72 jointly; The electric signal that arrowband bandpass filtering amplifying circuit 71 is exported infrared eye 5 carries out transferring to analog to digital conversion circuit 72 after filtering, amplification, and the voltage signal after filtering, amplification has the identical cycle with the signal of the driving light source modulation drive circuit 74 of microprocessor 73; The signal output part of temperature sensor 6 is connected with the analog input end of analog to digital conversion circuit 72; The digital output end of analog to digital conversion circuit 72 is connected with the signal input part of microprocessor 73, and analog to digital conversion circuit 72 all transfers the electric signal of the temperature signal receiving and each infrared sensor to and inputs to microprocessor 73 after digital signal again and process; Microprocessor 73 is according to the digital quantity receiving, and carries out analyzing and processing, temperature compensation, calculates the concentration of gas to be measured; The signal output part of microprocessor 73 is connected with the signal input part of modulation of source driving circuit 74; Microprocessor 73 is responsible for producing periodic control signal, and described periodic control signal is square wave; Modulation of source driving circuit 74 converts the cyclic control signal receiving to the voltage-drop loading of same period on light source 4, make light source 4 produce periodic radiation light-wave, this radiation light-wave is after gas absorption to be measured in air chamber 9 sidewall reflects and air chamber 9, be radiated on the photosurface of infrared eye 5, convert electric signal to; Microprocessor 73 is connected with interface 75, realizes being connected of microprocessor 73 and long-range host computer by interface 75.
Say further, in infrared eye 5, each infrared sensor is all connected with an arrowband bandpass filtering amplifying circuit 71; Each arrowband bandpass filtering amplifying circuit 71 is connected with an analog to digital conversion circuit 72 multi-analog input ends jointly; Arrowband bandpass filtering amplifying circuit 71 is made up of the first resistance R 1, the second resistance R 2, the first capacitor C 1, the second capacitor C 2 and operational amplifier OP; Wherein, between the output terminal of operational amplifier OP and negative input end, be parallel with the first resistance R 1 and the first capacitor C 1; The negative input end of operational amplifier OP is connected with one end of the second resistance R 2, and the other end of the second resistance R 2 is connected with one end of the second capacitor C 2; The other end of the second capacitor C 2 is connected with the power supply negative terminal of infrared eye 5; The positive input terminal of operational amplifier OP is connected with the output terminal of infrared sensor; The output terminal of operational amplifier OP is connected with analog to digital conversion circuit 72; The transition function of arrowband bandpass filtering amplifying circuit 71 is:
Figure 2014100942493100002DEST_PATH_IMAGE001
Regulate by the parameter to resistance R 1, R2, capacitor C 1, C2, realize arrowband bandpass filtering amplifying circuit 71 centre frequency f 0, bandwidth f w, enlargement factor A 0, quality factor q control.
Say further, the wick of light source 4 is tungsten filament or thermal resistance film; Under "on" position, light source 4 generates heat and produces infrared radiation; Modulation of source driving circuit 74 is made up of light source 4, the 3rd resistance R 3, the 4th resistance R 4, the 5th resistance R 5, the 6th resistance R 6, triode VT1 and field effect transistor VT2; Wherein, the source electrode of field effect transistor VT2 connects power supply ground, the source electrode of field effect transistor VT2 is connected by the 6th resistance R 6 with the drain electrode of field effect transistor VT2, the drain electrode of field effect transistor VT2 connects the 5th resistance R 5, the gate pole of field effect transistor VT2 is connected with one end of the 4th resistance R 4, the emitter of triode VT1 respectively, the other end of the 4th resistance R 4 connects power supply VCC, triode VT1 collector is connected with the source electrode of field effect transistor VT2, the base stage of triode VT1 is connected with one end of the 3rd resistance R 3, and the other end of the 3rd resistance R 3 is connected with microprocessor 73; Between the other end of the 4th resistance R 4 and the other end of the 5th resistance R 5, be in series with light source 4; Be flow through successively light source 4, the 5th resistance R 5, the 6th resistance R 6 and field effect transistor VT2 of electric current that power supply VCC provides, realize the power supply to light source 4, the cyclic control signal that microprocessor 73 produces is successively through the 3rd resistance R 3, triode VT1 and field effect transistor VT2, and driving light source 4 periodically sends radiation light-wave; Tungsten filament passes into current flow heats, temperature raise, along with the rising of temperature, tungsten filament resistance value increase, do not have electric current by time resistance be called cold resistance, in the time having electric current to pass through, resistance will raise, and be called thermal resistance; Tungsten filament cold resistance is very little, if light source 4 is lighted from cold resistance state, this process can produce very large dash current; Modulation of source driving circuit 74, by loading certain electric current on light source 4, has avoided light source 4 to light from cold resistance state;
When field effect transistor VT2 cut-off, power supply VCC arrives power supply ground through light source 4, resistance R 5, R6, can set by light source 4 current values by regulating resistance R6, determine light source 4 depth of modulation, when namely being on the scene effect pipe VT2 cut-off, in light source 4, pass into electric current, while avoiding light source 4 cold resistance states to light, to the impact of power supply VCC;
Field effect transistor VT2 is the N-channel MOS FET of low on-resistance, conducting resistance only several ohm of zero points; When field effect transistor VT2 conducting, power supply VCC arrives power supply ground through light source 4, resistance R 5, field effect transistor VT2 and the leakage, source resistance R6 that are parallel to field effect transistor VT2, set by light source 4 current values by regulating resistance R5, determine the radiant light wave intensity that light source 4 produces;
Triode VT1 mono-is for the protection of field effect transistor VT2, prevents that field effect transistor VT2 from damaging, the 2nd, and the control signal that microprocessor 73 is exported and light source 4 power supply VCC isolate, and prevent phase mutual interference.
The detection method of infrared gas sensor provided by the present invention; Measure as follows:
Measuring process one, initialization; Microprocessor 73 is exported cyclic control signal, described cyclic control signal is square wave, light source 4 just periodically sends radiation light-wave, the heat that radiation light-wave produces periodically heats gas indoor gas, impel gas indoor gas to carry out the circulation of " expand-shrink ", carry out sufficient gas exchange with environment, air chamber 9 is dried, is cleaned;
Measuring process two, signals collecting; Microprocessor 73 is exported channel coding and the instruction of sampled signal, respectively temperature, each point voltage, infrared eye 5 output signals is gathered and be converted to digital signal; To each sensitive element output of infrared eye 5 through amplifying, filtered sine wave, after cyclic control signal makes in light source 4 electric current from large to small, carry out 128～1024 samplings;
Measuring process three, calculates; Temperature, each point voltage, infrared eye 5 are exported, in the time that signals collecting is idle, calculated, concrete is at cyclic control signal, electric current in light source 4 to be calculated after changing from small to big;
Wherein, in infrared eye 5, the output signal of each sensitive element is sinusoidal wave after arrowband bandpass filtering amplifying circuit 71 is processed, and samples, and calculate by following formula in a sine wave:
Figure 763359DEST_PATH_IMAGE002
In formula, u mfor the analog sine measured value after gas absorption infrared energy to be measured, u rfor all gas to be measured does not all absorb the analog sine reference value after infrared energy, U mfor measured value u mpeak value, U rfor reference value u rpeak value, u m/ u rrepresenting the numerical value of a certain gas concentration to be measured, is the peakedness ratio of measured value and reference value sine function waveform, and n is sampling number in one-period, and the value of n is between 128～1024;
Measuring process four, self-inspection; The numerical value such as export and compare with the regime values that microprocessor 73 stores calculating gained temperature, each point voltage, infrared eye 5, judge whether to exist fault, when fault, export fault type code;
Measuring process five, temperature compensation; Comprise zero temperature compensation and two steps of range temperature compensation to calculating the temperature compensation that the concentration parameter of gas carries out, obtain subsequently gas concentration value after temperature compensation;
Wherein, at real time temperature T ttime, the formula of zero temperature compensation is:
Figure 2014100942493100002DEST_PATH_IMAGE003
In formula, k 0be zero temperature compensation coefficient, a is temperature T 0time be stored in the value in microprocessor 73 memories, a treal time temperature T ttime offset;
At real time temperature T ttime, the formula of range temperature compensation is:
In formula, k srange temperature compensation coefficient, a treal time temperature T ttime offset, b is temperature T 0time be stored in the value in microprocessor 73 memories, u m/ u rreal time temperature T ttime measured value, c is the concentration value of the gas to be measured that will calculate after temperature compensated;
Measuring process six, converts the gas concentration value after the temperature compensation of step 5 to analog quantity or digital quantity signal, and transmits through interface 75.
For the constant a and range constant b, zero temperature compensation coefficient k at zero point in this product sensor measuring method 0with range temperature compensation coefficient k sbe by after sensor is demarcated and calculated, deposit in microprocessor 73 memories, time to be measured, transfer and use.
useful technique effect
1, light source is periodically to air chamber heating, and in air chamber, gas " expand-shrink ", forms respiratory air chamber, after sensor powers on, air chamber is dried, and in air chamber, gas " expand-shrink ", eliminates steam, the impact of dust on light path, optical system and air chamber;
Respiratory air chamber can with the abundant exchanging gas of environment, shortened response time of sensor, improved the reliability that environmental gas is detected;
The two is integrated air chamber heating and light source, with common by well heater to compared with air chamber heating, sensor construction compactness, power consumption reduce greatly, have also improved the explosion-proof performance of sensor;
Described modulation of source control circuit makes periodically light on and off of light source, in the half period of not lighting at light source, load certain electric current on light source, with common light source from the cold resistance state point ratio that exposes, avoid light source to light the dash current of generation from cold resistance state, thereby met the requirement of essential safety source power supply under coal mine; Meanwhile, described modulation of source control circuit, limits and controls the energy of light source, and making its type of protection [of an electrical apparatus for explosive atmospheres is essential safe type;
2, the Stability and dependability for ensureing that sensor moves for a long time in rugged surroundings under coal mine, this patent has been taked following technical measures:
(1) adopt ripe measurement and with reference to sensitive element testing compensation technique, light path and optical system compensated, eliminating light intensity in light source fluctuation, light path and be disturbed the impact causing;
(2) described temperature compensation, eliminates the impact that caused by temperature variation;
(3) described wire netting and filtering membrane can intercept steam, dust enters air chamber; Described air chamber heating, after sensor powers on, is dried air chamber, and in air chamber, gas " expand-shrink ", eliminates steam, the impact of dust on light path, optical system and air chamber;
(4) described air chamber inwall covers reflective membrane (gold-plated), except having improved reflection of light efficiency, also prevents the corrosion of corrosive gas;
3, from circuit and structure, the technical measures that the explosion-proof performance of sensor is taked: described modulation of source control circuit, the energy of light source is limited and controlled, its type of protection [of an electrical apparatus for explosive atmospheres is essential safe type, even if light source breaks down or damages, do not affect explosion-proof performance yet; If described modulation of source control circuit also breaks down or damages, described wire netting can play flame proof effect, makes to be transferred to energy in external environment and is restricted;
4, air chamber is the space that described shell and described Inner cylindrical shell surround, outer casing inner wall and Inner cylinder body outer wall have formed camber reflection optical system, light has formed the light path that detects gas through multiple reflections, air chamber and optical system are integrated, there is no optical concentration, beam splitting system, air chamber structure is simple, volume is little, lightweight, processing, assemble easy, according to light source, the device installing spaces such as infrared eye, and the quantity of detection gas composition, resolution, the requirement of precision, change described shell and described Inner barrel diameter and height, just increase or reduce air chamber capacity and light path light path, meet the various requirement that gas is detected, optimize structure and the volume of sensor,
5, the centre frequency of described arrowband bandpass filtering amplifying circuit is consistent with the frequency of modulation of source, this frequency signal is carried out to narrow-band filtering, the electric signal that output infrared radiation that infrared sensor receives produces, thereby, eliminate the interference of background and other noises, even if this signal is submerged in noise, arrowband bandpass filtering amplifying circuit also can be exported this frequency signal, has processing power and the antijamming capability of very strong signal; Form arrowband bandpass filtering amplifying circuit by a low noise operational amplifier, filtering, amplification, the function such as anti-interference are completed by one-level circuit, circuit is simple, reliable, debugging is convenient, cost is low, antijamming capability is strong;
6, each parts, through suitable cooperation, are realized sensor and are carried out the detection of multiple gases concentration simultaneously:
(1) the infrared radiation wave band of described light source is contained 2～5 μ m, 8～12 μ m, 2～12 μ m and 2～20 μ m, comprise the characteristic wavelength of all gas absorption infrared radiations to be measured, the radiation spectrum of light source has the characteristic wavelength of the gas absorption infrared radiation that simultaneously carries out the detection of multiple gases concentration;
(2) described infrared eye is polynary pyroelectric infrared detector, formed by multiple infrared sensors, on the sensitive area of each infrared sensor reception infrared radiation, spike interference filter is installed, spike interference filter plays optical filtering, only allow the infrared radiation of the characteristic wavelength that corresponding gas to be measured will absorb pass through, only have the infrared radiation of gas characteristic absorbing wavelength to be measured to arrive infrared sensor, therefore, can select various types of gas measurement;
(3) described inner barrel, for the space of installation infrared detector, can be adjusted according to the volume of infrared eye with to gasmetry precision, is convenient to the installation of the multielement infrared detector of multiple infrared sensor compositions;
(4) optical system that described air chamber forms, light path reflects through gas chamber sidewall, infrared eye described in the hot spot direct irradiation forming, without optical device, described light source is sent that light converges or light splitting, only just arrive described infrared eye through reflection, the detection of the infrared eye of applicable multiple sensitive areas to infrared radiation can detect multiple gases light path simultaneously;
7, described calibration mode, zero point, range, zero temperature compensation coefficient and range temperature compensation coefficient to sensor are demarcated, and have ensured that sensor detects accuracy and the precision of gas; The all parameters of calibration process complete automatically to be calculated and storage, easy and simple to handle, is a kind of transducer calibration pattern of novelty;
8, described signals collecting, calculating are the principles that detects gas concentration according to the characteristic of sine function and Lambert-Beer's law, and each sensitive element output of described infrared eye, through amplification, filtered sine wave, is carried out to n sampling in one-period; Compared with once sampling with common one-period, feature of the present invention is in one-period, to carry out n sampling, be equivalent in time n cycle to sample, be all equivalent to be chosen in peak value place in the sampling of the arbitrfary point of sine function waveform, thereby, improve the fiduciary level of signals collecting, increase antijamming capability, reduced the sampling time, saved the time of microprocessor time delay, wait, improve program operational efficiency, shortened the sensor response time;
9, described zero temperature compensation and range temperature compensation, the arbitrary concentration value that detects gas has all been carried out to temperature compensation, avoid existing sensor there is no temperature compensation, or the only temperature compensation to zero point or several sampling spots, be a kind of Sensor Temperature Compensation method of novelty.
Brief description of the drawings
Fig. 1 is the longitudinal sectional view of this product.
Fig. 2 is the A-A cut-open view of Fig. 1.
Fig. 3 is the assembly drawing of Fig. 1.
Fig. 4 is the B-B cut-open view of Fig. 1.
Fig. 5 is the structured flowchart of this product signal treatment circuit.
Fig. 6 is the circuit diagram of modulation of source driving circuit 74.
Fig. 7 is that in Fig. 6, modulation of source driving circuit 74 is carried in electric current and the voltage waveform view on light source 4.
The circuit diagram of Fig. 8 arrowband bandpass filtering amplifying circuit 71.
Fig. 9 is the process flow diagram under this product measurement pattern.
Figure 10 is the process flow diagram under this product calibration mode.
concrete embodiment
Now be described with reference to the accompanying drawings the technical characterstic of this patent.
Referring to Fig. 1, a kind of infrared gas sensor, comprises shell 1, Inner cylindrical shell 2 and circuit unit; Wherein, there is shell 1 in the outer cover of Inner cylindrical shell 2, be connected with circuit unit in the bottom of Inner cylindrical shell 2;
Referring to Fig. 1 and Fig. 3, described shell 1 is hollow cylinder, is provided with the step 11 of inside stretching, extension on the top of shell 1; Described step 11 ringwise; Be covered with one deck filtering membrane 12 at the main header casing of step 11; Described filtering membrane 12 is the hydrophobic film of waterproof and ventilation; Be covered with layer of metal net 13 in the bottom of step 11, described wire netting 13, for aperture is the circular stainless steel wire mesh that 60～80 orders and thickness are greater than 1mm, is provided with vent board 14 in the bottom surface of wire netting 13; Described vent board 14 is thin sheet of metal plate-like, is evenly equipped with through hole 15 at the edge of vent board 14, and the quantity of through hole 15 is between 10 to 30; By filtering membrane 12, wire netting 13 and vent board 14, the opening at shell 1 top is covered, as shown in Figure 4;
Referring to Fig. 2 and Fig. 3, described Inner cylindrical shell 2 is the hollow cylinder of top sealing, be provided with outward extending annular edge 21 in the bottom of Inner cylindrical shell 2, be provided with a light inlet 22 on the sidewall of Inner cylindrical shell 2, the opening angle α of described light inlet 22 is between 60～80 ° and contour with Inner cylindrical shell 2; In annular edge 21, be provided with an accurate tri-prismoid, described accurate tri-prismoid by reflecting plate 23, light barrier 24 and arc 26 around forming, wherein, reflecting plate 23 is connected with the corner angle limit of light barrier 24 connecting places and Inner cylindrical shell 2 sidewalls in light inlet 22 left sides, and one section of edge of the base of arc 26 and annular edge 21 coincides; Be provided with a through hole 25 near in the annular edge 21 of light barrier 24;
Referring to Fig. 1, the bottom surface close contact of the end face of Inner cylindrical shell 2 and vent board 14; The annular edge 21 of Inner cylindrical shell 2 is joined with the inwall of shell 1; Annular edge 21 is filled with epoxy sealing with the junction of shell 1; The region that shell 1 and inner barrel 2 surround forms the air chamber 9 of this infrared gas sensor; Be that external environment gas is successively through the rear diffusion of through hole 15 of filtering membrane 12, wire netting 13 and vent board 14 air inlet chamber 9 of going forward side by side;
Described circuit unit comprises base plate 3, light source 4, infrared eye 5, temperature sensor 6 and signal processing circuit 7; Described base plate 3 is circular metal plate and isometric with the external diameter of annular edge 21; The end face of base plate 3 is connected with the bottom surface of annular edge 21, by base plate 3, the opening of Inner cylindrical shell 2 belows is sealed, as shown in figures 1 and 3;
Referring to Fig. 1 and Fig. 2, the central authorities of base plate 3 end faces that surround at Inner cylindrical shell 2 are provided with infrared eye 5; Be provided with temperature sensor 6 near on base plate 3 end faces of infrared eye 5; Light source 4 is arranged on air chamber 9 ends near light barrier 24 1 sides, and the bottom of light source 4 is connected with base plate 3 through through hole 25 is rear, and light source 4 via through holes 25 extend in air chamber 9; Signal processing circuit 7 is placed on base plate 3, and by wire, the infrared eye 5 of base plate 3 end faces, temperature sensor 6 and light source 4 is connected with signal processing circuit 7 respectively;
The control end of described signal processing circuit 7 is connected with light source 4, to the voltage of light source 4 transport cycle; The signal input part of signal processing circuit 7 is connected with the signal output part of infrared eye 5 and temperature sensor 6 respectively;
Referring to Fig. 5, described light source 4 produces periodic radiation light-wave under the driving of periodic voltage; The periodicity radiation light-wave that light source 4 produces is radiated on infrared eye 5 through air chamber 9 multiple reflections and through light inlet 22; The periodicity radiation light-wave that light source 4 produces is on the one hand as the infrared radiation light wave that detects use, on the other hand the gas in air chamber 9 is periodically heated, impel the periodically dilation of gas in air chamber 9, carry out rapidly gas exchange thereby realize gas in air chamber 9 and the environmental gas of shell 1 outside, formed " respiratory air chamber ";
Described infrared eye 5 is produced periodically radiation light-wave by what receive by light source 4, be converted into the electric signal of radiation light-wave same period after be passed to signal processing circuit 7;
Described temperature sensor 6 detects in real time near temperature infrared eye 5 and is passed to signal processing circuit 7, and the electric signal of infrared eye 5 being passed back for signal processing circuit 7 does temperature compensation.
Say further, the spectral range of the radiation light-wave that light source 4 sends is that visible ray is to infrared band.Wherein, the preferred wavelength band of infrared radiation is 2～5 μ m, 8～12 μ m, 2～12 μ m and 2～20 μ m; Infrared eye 5 is made up of 2 to 16 infrared sensors, wherein 1 infrared sensor reception wavelength is the infrared radiation of 3.9 μ m, on the sensitive area of remaining infrared sensor, spike interference filter is all installed, receives the infrared radiation with the corresponding wavelength of spike interference filter; The radiation light-wave that light source 4 sends is after the multiple reflections of air chamber 9, and the hot spot direct irradiation of formation, on the whole sensitive area of infrared eye 5, does not add any converging or the optical device of light splitting in whole light path.
Referring to Fig. 5, described signal processing circuit 7 is made up of arrowband bandpass filtering amplifying circuit 71, analog to digital conversion circuit 72, microprocessor 73, modulation of source driving circuit 74 and interface 75; The signal output part of each infrared sensor of infrared eye 5 is all connected with an arrowband bandpass filtering amplifying circuit 71; The signal output part of each arrowband bandpass filtering amplifying circuit 71 is connected with the multi-analog input end of analog to digital conversion circuit 72 jointly; The electric signal that arrowband bandpass filtering amplifying circuit 71 is exported infrared eye 5 carries out transferring to analog to digital conversion circuit 72 after filtering, amplification, and the voltage signal after filtering, amplification has the identical cycle with the signal of the driving light source modulation drive circuit 74 of microprocessor 73; The signal output part of temperature sensor 6 is connected with the analog input end of analog to digital conversion circuit 72; The digital output end of analog to digital conversion circuit 72 is connected with the signal input part of microprocessor 73, and analog to digital conversion circuit 72 all transfers the electric signal of the temperature signal receiving and each infrared sensor to and inputs to microprocessor 73 after digital signal again and process; Microprocessor 73 is according to the digital quantity receiving, and carries out analyzing and processing, temperature compensation, calculates the concentration of gas to be measured; The signal output part of microprocessor 73 is connected with the signal input part of modulation of source driving circuit 74; Microprocessor 73 is responsible for producing periodic control signal, and described periodic control signal is square wave; Modulation of source driving circuit 74 converts the cyclic control signal receiving to voltage-drop loading on light source 4, make light source 4 produce periodic radiation light-wave, this radiation light-wave is after gas absorption to be measured in air chamber 9 sidewall reflects and air chamber 9, be radiated on the photosurface of infrared eye 5, convert electric signal to; Microprocessor 73 is connected with interface 75, realizes being connected of microprocessor 73 and long-range host computer by interface 75.
Say further, in infrared eye 5, each infrared sensor is all connected with an arrowband bandpass filtering amplifying circuit 71; Each arrowband bandpass filtering amplifying circuit 71 is connected with an analog to digital conversion circuit 72 multi-analog input ends jointly; Referring to Fig. 8, arrowband bandpass filtering amplifying circuit 71 is made up of the first resistance R 1, the second resistance R 2, the first capacitor C 1, the second capacitor C 2 and operational amplifier OP; Wherein, between the output terminal of operational amplifier OP and negative input end, be parallel with the first resistance R 1 and the first capacitor C 1; The negative input end of operational amplifier OP is connected with one end of the second resistance R 2, and the other end of the second resistance R 2 is connected with one end of the second capacitor C 2; The other end of the second capacitor C 2 is connected with the power supply negative terminal of infrared eye; The positive input terminal of operational amplifier OP is connected with the output terminal of infrared sensor; The output terminal of operational amplifier OP is connected with analog to digital conversion circuit 72; The transition function of arrowband bandpass filtering amplifying circuit 71 is:
Figure 502087DEST_PATH_IMAGE001
（I）
By the parameter of resistance R 1, R2, capacitor C 1, C2 in formula (I) is regulated, realize arrowband bandpass filtering amplifying circuit 71 centre frequency f 0, bandwidth f w, enlargement factor A 0, quality factor q control.
Taking light source 4 glow frequencies as 4Hz is as example, the realization of parameter described in arrowband bandpass filtering amplifying circuit 71 is described:
Corresponding with light source 4 modulating frequencies, arrowband bandpass filtering amplifying circuit 71 centre frequency f 0=4Hz; Bandwidth is as far as possible narrow, is not the undesired signal of 4Hz with filtering as much as possible, selects bandwidth f w=8Hz; For preventing the self-oscillatory generation of amplifying circuit and the amplitude versus frequency characte below bandwidth sharply declined, the quality factor q <1 of wave filter;
Calculate according to described transition function H (s), the parameter that can obtain resistance R 1, R2, capacitor C 1, C2 meets the parameter request of arrowband bandpass filtering amplifying circuit 71, shown in table 1, is to have provided several groups of typical parameter values:
The parameter of table 1 arrowband bandpass filtering amplifying circuit 71 regulates
At centre frequency f 0, bandwidth f w, quality factor q constant under, adjustable resistor R1, R2 reach the requirement of arrowband bandpass filtering amplifying circuit 71 enlargement factors.
Say further, light source 4 is low frequency electrical modulation broadband infrared light source, and infrared radiation wave band is contained 2～5 μ m, 8～12 μ m, 2～12 μ m and 2～20 μ m, and wick is tungsten filament or thermal resistance film, heating after energising, the infrared radiation of generation;
Referring to Fig. 6, modulation of source driving circuit 74 is made up of light source 4, the 3rd resistance R 3, the 4th resistance R 4, the 5th resistance R 5, the 6th resistance R 6, triode VT1 and field effect transistor VT2; Wherein, the source electrode of field effect transistor VT2 connects power supply ground, the source electrode of field effect transistor VT2 is connected by the 6th resistance R 6 with the drain electrode of field effect transistor VT2, the drain electrode of field effect transistor VT2 connects the 5th resistance R 5, the gate pole of field effect transistor VT2 is connected with one end of the 4th resistance R 4, the emitter of triode VT1 respectively, the other end of the 4th resistance R 4 connects power supply VCC, triode VT1 collector is connected with the source electrode of field effect transistor VT2, the base stage of triode VT1 is connected with one end of the 3rd resistance R 3, and the other end of the 3rd resistance R 3 is connected with microprocessor 73; Between the other end of the 4th resistance R 4 and the other end of the 5th resistance R 5, be in series with light source 4; Be flow through successively light source 4, the 5th resistance R 5, the 6th resistance R 6 and field effect transistor VT2 of electric current that power supply VCC provides, realize the power supply to light source 4, the cyclic control signal that microprocessor 73 produces is successively through the 3rd resistance R 3, triode VT1 and field effect transistor VT2, and driving light source 4 periodically sends radiation light-wave; Tungsten filament passes into current flow heats, temperature raise, along with the rising of temperature, tungsten filament resistance value increase, do not have electric current by time resistance be called cold resistance, in the time having electric current to pass through, resistance will raise, and be called thermal resistance; Tungsten filament cold resistance is very little, if light source 4 is lighted from cold resistance state, this process can produce very large dash current; Modulation of source driving circuit 74, by loading certain electric current on light source 4, has avoided light source 4 to light from cold resistance state;
When field effect transistor VT2 cut-off, power supply VCC arrives power supply ground through light source 4, resistance R 5, R6, can set by light source 4 current values by regulating resistance R6, determine light source 4 depth of modulation, when namely being on the scene effect pipe VT2 cut-off, in light source 4, pass into electric current, while avoiding light source 4 cold resistance states to light, to the impact of power supply VCC;
Field effect transistor VT2 is the N-channel MOS FET of low on-resistance, conducting resistance only several ohm of zero points; When field effect transistor VT2 conducting, power supply VCC arrives power supply ground through light source 4, resistance R 5, field effect transistor VT2 and the leakage, source resistance R6 that are parallel to field effect transistor VT2, set by light source 4 current values by regulating resistance R5, determine the radiant light wave intensity that light source 4 produces.
Referring to Fig. 7, light source 4 modulating frequencies are 4Hz(cycle 0.25s); When field effect transistor VT2 cut-off, by regulating resistance R6, light source 4 electric currents are 10mA, and now light source 4 is not lighted; When field effect transistor VT2 conducting, by regulating resistance R5, light source 4 electric currents are 60mA, and now light source 4 is lighted; Conventionally the modulation of source driving circuit adopting, in the time that light source is not lighted, the electric current that modulation of source driving circuit loads is 0, like this, light source is just lighted under cold resistance state, power supply is produced to very large dash current, and this causes adverse effect for essential safety source power supply under coal mine, makes sensor not power on or to work undesired.
Triode VT1 mono-is for the protection of field effect transistor VT2, prevents that field effect transistor VT2 from damaging, the 2nd, and the control signal that microprocessor 73 is exported and light source 4 power supply VCC isolate, and prevent phase mutual interference.
In addition, sensor explosion-proof performance is realized by modulation of source driving circuit 74 and wire netting 13;
Modulation of source driving circuit 74 is controlled the electric current or the restriction energy that offer light source 4, makes light source 4 and signal processing circuit 7 meet the requirement of GB3836.4 essential safety; In the situation that 74 safeguard protections of modulation of source driving circuit were lost efficacy, wire netting 13 should ensure to reach back-fire relief, explosion-proof functional requirement, thereby realizes sensor explosion prevention function, can be used for the concentration of explosion hazard environment measuring gas to be measured; In addition, filtering membrane 12 ensures air chamber and extraneous exchanging gas, does not allow steam enter air chamber, realizes the water-proof function of sensor, can use having in steam, high humidity environment.
Referring to Fig. 9, adopt infrared gas sensor provided by the present invention to carry out as follows the measurement of gas:
Measuring process one, initialization; Microprocessor 73 is exported cyclic control signal, described cyclic control signal is square wave, light source 4 just periodically sends radiation light-wave, the heat that radiation light-wave produces periodically heats gas indoor gas, impel gas indoor gas to carry out the circulation of " expand-shrink ", carry out sufficient gas exchange with external environment, air chamber 9 is dried, is cleaned; After sensor powers on, field effect transistor VT2 cut-off, light source 4 flows through small electric stream through resistance R 6, when avoiding light source 4 to be powered on by cold resistance, occurs heavy current impact; After approximately 5 seconds, microprocessor 73 is exported cyclic control signal, light source 4 just periodically sends radiation light-wave, its heat carries out periodicity heating to air chamber 9 simultaneously, make gas indoor gas carry out " expand-shrink " circulation, carry out sufficient gas exchange with external environment, also played the function of dehumidifying, dedusting, heat approximately 1 minute; Microprocessor 73 is read and write and is checked each calibrating parameters in memory;
Measuring process two, signals collecting; Microprocessor 73 is exported channel coding and the instruction of sampled signal, and analog to digital conversion circuit 72 receives instruction, opens corresponding passage, respectively temperature, each point voltage, infrared eye 5 output signals is gathered and be converted to digital signal; To each sensitive element output of infrared eye 5 through amplifying, filtered sine wave, after cyclic control signal makes in light source 4 electric current from large to small, carry out 128～1024 samplings;
Measuring process three, calculates; Temperature, each point voltage, infrared eye 5 are exported, in the time that signals collecting is idle, calculated, concrete is at cyclic control signal, electric current in light source 4 to be calculated after changing from small to big;
Temperature, voltage are direct current signals, repeatedly, after sampling, calculate and just can through arithmetic mean;
In infrared eye 5, the output signal of each sensitive element is sine wave after arrowband bandpass filtering amplifying circuit 71, common way is once to sample at one-period, and at this sinusoidal wave peak value place, although the amplitude of this sampled value is large, but owing to only having carried out once sampling, reliability and the antijamming capability of actual acquisition signal are poor; Patent of the present invention is according to the characteristic of sine function and the principle of Lambert-Beer's law detection gas concentration, after cyclic control signal makes in light source 4 electric current from large to small, repeatedly sample (samplings of 128～1024 times) and calculate by formula (II):
Figure DEST_PATH_IMAGE007
(II)
In formula (II): u mfor the analog sine measured value after a certain gas absorption infrared energy to be measured, u rfor all gas to be measured does not all absorb the analog sine reference value after infrared energy, U mfor measured value u mpeak value, U rfor reference value u rpeak value, u m/ u rrepresenting the numerical value of gas concentration to be measured, is the peakedness ratio of measured value and reference value sine function waveform, and n is that one-period carries out sampling number, and the span of n is between 128～1024; Compared with once sampling with common one-period, feature of the present invention is in one-period, to carry out n sampling, be equivalent in time n cycle to sample, be all equivalent to be chosen in peak value place in the sampling of the arbitrfary point of sine function waveform, thereby, improve the fiduciary level of signals collecting, increase antijamming capability, reduced the sampling time, saved the time of microprocessor 73 time delays, wait, improve program operational efficiency, shortened the sensor response time; u m/ u rfollow Lambert-Beer's law with the relation of gas concentration c to be measured:
Figure 201239DEST_PATH_IMAGE008
(III)
In formula (III): a and b are constant, be stored in the memory of microprocessor 73, can calculate thus gas concentration c to be measured;
Measuring process four, self-inspection; Temperature, each point voltage, infrared eye 5 detected value such as are exported and are compared with the regime values that microprocessor 73 stores, and judge whether to exist fault, when fault, and output fault type code;
To detect that supply voltage, the voltage of light source 4 and the voltage of each monitoring point compares with the regime values that microprocessor 73 stores, can judge the trouble spot of supply voltage superelevation or ultralow, light source 4 open circuits or short circuit or damage, circuit; When fault, the fault type code of interface 75 out-put supplies or light source or circuit;
Diagnosis temperature whether in normal range, thereby judge temperature sensor 6 open circuits or short circuit or damage; When fault, the fault type code of interface 75 output temperatures;
Detect measuring-signal that infrared eye 5 transmission comes whether in the normal range of gas to be measured, thereby judge and work infrared eye 5 whether normal, optical system and light path be normal, when fault, interface 75 is exported the fault type code of infrared eye and light path; Close to normal range by the undesired value of infrared eye 5 being detected, to judge the processing of just carrying out the pollutions such as steam in air chamber 9, interface 75 is exported the clean code of air chamber, air chamber 9 has carried out sufficient gas exchange through heating and with environment, air chamber is dry, after dedusting, just can enter normal operating conditions;
In the trouble-free situation of sensor self-inspection, automatically enter measurement pattern;
Measuring process five, temperature compensation; Comprise zero temperature compensation and two steps of range temperature compensation to calculating the temperature compensation that the concentration parameter of gas carries out, obtain subsequently gas concentration value after temperature compensation;
The calculating concentration c that step 3 Chinese style (III) is described is that temperature is T within the scope of senor operating temperature (as: senor operating temperature is 0～40 DEG C) 0(as: T 0=13 DEG C) situation under carry out, due to measured value and reference value u m, u rtemperature influence, obtains real-time temperature by temperature sensor 6, carries out temperature compensation, can measure exactly the concentration of gas to be measured; Temperature compensation has zero temperature compensation and range temperature compensation; At real time temperature T t(as: T t=33 DEG C) time, be exactly zero temperature compensation to the compensation of a value in formula (III):
Figure 2014100942493100002DEST_PATH_IMAGE009
(IV)
In formula (IV): k 0be zero temperature compensation coefficient, a is temperature T 0time be stored in the value in microprocessor 73 memories, a treal time temperature T ttime offset;
At real time temperature T t(as: T t=33 DEG C) time, to u in formula (III) m/ u rthe compensation of value is exactly range temperature compensation:
Figure 468272DEST_PATH_IMAGE010
(V)
In formula (V): k srange temperature compensation coefficient, a treal time temperature T ttime offset, b is temperature T 0time be stored in the value in microprocessor 73 memories, u m/ u rreal time temperature T ttime measured value, c is the concentration value of the gas to be measured that will calculate after temperature compensated;
Measuring process six, converts the gas concentration value after the temperature compensation of step 5 to analog quantity or digital quantity signal, transmits through interface 75.
The concentration c being calculated by formula (V), is the measured gas concentration to be measured after temperature compensated; Gas concentration, according to corresponding standard or standard, converts analog quantity or digital quantity signal to, carries out wired or wireless transmission through interface 75.
Referring to Figure 10, in this sensor measurement, Zero calibration constant a, the range designation constant b in microprocessor 73 memories, the temperature T of timing signal 0, zero temperature compensation coefficient k 0, range temperature compensation coefficient k svalue calculated under calibration mode by this product sensor, the method that its calibration mode is demarcated is carried out as follows:
Demarcating steps one, Zero calibration;
Infrared gas sensor is being demarcated temperature T 0under condition, in air chamber 9, pass into nitrogen (being gas concentration c=0 to be measured), until air chamber 9 is full of nitrogen completely, measure the analog sine measured value u after the gas absorption infrared energy to be measured of each infrared sensor mall do not absorb the analog sine reference value u after infrared energy with gas to be measured r, and calculate the value of constant a at zero point by formula (III), deposit in microprocessor 73 memories the temperature T that temperature sensor 6 measures in 0value also deposits in microprocessor 73 memories;
Demarcating steps two, range designation;
In the same temperature T of demarcating steps one 0time, in air chamber 9, pass into the Standard Gases sample that concentration is the gas to be measured of maximum range value, until air chamber 9 is full of the Standard Gases sample of this gas to be measured completely, measure the analog sine measured value u after the absorption infrared energy of each infrared sensor under the Standard Gases sample of this gas to be measured mwith under Standard Gases sample at this gas to be measured, do not absorb the analog sine reference value u after infrared energy rvalue, calculate the value of b by formula (III), deposit in microprocessor (73) memory;
Demarcating steps three, zero temperature compensation coefficient is demarcated;
Make the environment temperature of temperature sensor 6 rise or drop to T t, again in air chamber 9, pass into nitrogen (being gas concentration c=0 to be measured), until air chamber 9 is full of nitrogen completely, measures and calculate u m/ u rvalue, temperature is T ttime constant a at zero point tvalue, by the zero temperature compensation formula (IV) in measuring process five, calculates k 0value, deposits in microprocessor 73 memories;
Demarcating steps four, range temperature compensation coefficient is demarcated;
Continue the environment temperature of temperature sensor 6 to remain on T tunder state, be T toward passing into temperature in air chamber 9 t, concentration is the Standard Gases sample of the gas to be measured of maximum range value, measure and calculate u m/ u rvalue, calculate k by the range temperature compensation formula (V) in measuring process five svalue and deposit in microprocessor 73 memories, time to be measured, call; After transducer calibration completes, return measurement pattern.

Claims (8)

1. an infrared gas sensor, comprises shell (1), Inner cylindrical shell (2) and circuit unit; Wherein, there is shell (1) in the outer cover of Inner cylindrical shell (2), be connected with circuit unit in the bottom of Inner cylindrical shell (2); It is characterized in that: described shell (1) is hollow cylinder, be provided with the step (11) of inside stretching, extension on the top of shell (1); Described step (11) ringwise; Be coated with one deck filtering membrane (12) at the top of step (11); Be covered with layer of metal net (13) in the bottom of step (11), the bottom surface of wire netting (13) is connected with vent board (14); Described vent board (14) is thin sheet of metal plate-like, is evenly equipped with a circle through hole (15) on vent board (14); By filtering membrane (12), wire netting (13) and vent board (14), the open top of shell (1) is covered; Described Inner cylindrical shell (2), for the hollow cylinder of top sealing, is provided with outward extending annular edge (21) in the bottom of Inner cylindrical shell (2), is provided with a light inlet (22) on the sidewall of Inner cylindrical shell (2); In annular edge (21), be provided with an accurate tri-prismoid, described accurate tri-prismoid by reflecting plate (23), light barrier (24) and arc (26) around forming, wherein reflecting plate (23) is connected with Inner cylindrical shell (2) sidewall in light inlet (22) left side with the corner angle limit of light barrier (24) connecting place, and one section of edge of the base of arc (26) and annular edge (21) coincides; Be provided with a through hole (25) near in the annular edge (21) of light barrier (24);
The bottom surface close contact of the end face of Inner cylindrical shell (2) and vent board (14); The annular edge (21) of Inner cylindrical shell (2) is joined with the inwall of shell (1); Be filled with epoxy sealing in annular edge (21) and the junction of shell (1); The region that shell (1) and inner barrel (2) surround forms the air chamber (9) of this infrared gas sensor; Be that external environment gas is successively through spreading the air inlet chamber (9) of going forward side by side after the through hole (15) of filtering membrane (12), wire netting (13) and vent board (14);
Described circuit unit comprises base plate (3), light source (4), infrared eye (5), temperature sensor (6) and signal processing circuit (7); Described base plate (3) is circular metal plate and isometric with the external diameter of annular edge (21); Base plate (3) is connected with the bottom surface of annular edge (21), by base plate (3), the opening of Inner cylindrical shell (2) below is sealed;
Central authorities at base plate (3) end face are provided with infrared eye (5); Be provided with temperature sensor (6) near on base plate (3) end face of infrared eye (5); Light source (4) is arranged on air chamber (9) end near light barrier (24) one sides, and the bottom of light source (4) is connected with base plate (3) through after through hole (25); It is upper that signal processing circuit (7) is placed in base plate (3), and by wire, infrared eye (5), temperature sensor (6) and light source (4) are connected with signal processing circuit (7) respectively;
The control end of described signal processing circuit (7) is connected with light source (4), to the voltage of light source (4) transport cycle; The signal input part of signal processing circuit (7) is connected with the signal output part of infrared eye (5) and temperature sensor (6) respectively;
Described light source (4) produces periodic radiation light-wave under the driving of periodic voltage; The periodicity radiation light-wave that light source (4) produces is radiated on infrared eye (5) after air chamber (9) reflection and through light inlet (22); The periodicity radiation light-wave that light source (4) produces periodically heats the gas in air chamber (9), impel the periodically dilation of gas in air chamber (9), carry out rapidly gas exchange thereby realize the outside environmental gas of the interior gas of air chamber (9) and shell (1), formed " respiratory air chamber ";
Infrared eye (5) is the periodicity radiation light-wave receiving, be converted into the electric signal of radiation light-wave same period after be passed to signal processing circuit (7);
Temperature sensor (6) detects in real time near temperature infrared eye (5) and is passed to signal processing circuit (7), and the electric signal of infrared eye (5) being passed back for signal processing circuit (7) does temperature compensation.
2. a kind of infrared gas sensor according to claim 1, is characterized in that, the spectral range of the radiation light-wave that light source (4) sends is that visible ray is to infrared band; Infrared eye (5) is made up of 2 to 16 infrared sensors, wherein to receive wavelength be the infrared radiation of 3.9 μ m for 1 infrared sensor, and the infrared radiation of spike interference filter and reception and the corresponding wavelength of spike interference filter is all installed on the sensitive area of remaining infrared sensor; The hot spot direct irradiation that the radiation light-wave that light source (4) sends forms after the multiple reflections of air chamber (9), on the whole sensitive area of infrared eye (5), does not add any converging or the optical device of light splitting in whole light path.
3. a kind of infrared gas sensor as claimed in claim 1, it is characterized in that, described signal processing circuit (7) is made up of arrowband bandpass filtering amplifying circuit (71), analog to digital conversion circuit (72), microprocessor (73), modulation of source driving circuit (74) and interface (75);
The signal output part of each infrared sensor of infrared eye (5) is all connected with an arrowband bandpass filtering amplifying circuit (71); The signal output part of each arrowband bandpass filtering amplifying circuit (71) is connected with the multi-analog input end of analog to digital conversion circuit (72) jointly; Arrowband bandpass filtering amplifying circuit (71) carries out the electric signal of infrared eye (5) output to transfer to analog to digital conversion circuit (72) after filtering, amplification, and the voltage signal after filtering, amplification has the identical cycle with the signal of the driving light source modulation drive circuit (74) of microprocessor (73);
The signal output part of temperature sensor (6) is connected with the analog input end of analog to digital conversion circuit (72);
The digital output end of analog to digital conversion circuit (72) is connected with the signal input part of microprocessor (73), and analog to digital conversion circuit (72) all transfers the electric signal of the temperature signal receiving and each infrared sensor to and inputs to microprocessor (73) after digital signal again and process; Microprocessor (73) is according to the digital quantity that receives, carries out analyzing and processing, temperature compensation, calculates the concentration of gas to be measured;
The signal output part of microprocessor (73) is connected with the signal input part of modulation of source driving circuit (74); Microprocessor (73) is responsible for producing periodic control signal, and described periodic control signal is square wave; Modulation of source driving circuit (74) is converted to synperiodic driving voltage by the cyclic control signal receiving and is carried on light source (4), make light source (4) produce periodic radiation light-wave, this radiation light-wave is after gas absorption to be measured in air chamber (9) sidewall reflects and air chamber (9), be radiated on the photosurface of infrared eye (5), convert electric signal to;
Microprocessor (73) is connected with interface (75), realizes being connected of microprocessor (73) and long-range host computer by interface (75).
4. a kind of infrared gas sensor according to claim 1, is characterized in that, in infrared eye (5), each infrared sensor is all connected with an arrowband bandpass filtering amplifying circuit (71); Each arrowband bandpass filtering amplifying circuit (71) is connected with the multi-analog input end of an analog to digital conversion circuit (72) jointly;
Arrowband bandpass filtering amplifying circuit (71) is made up of the first resistance R 1, the second resistance R 2, the first capacitor C 1, the second capacitor C 2 and operational amplifier OP; Wherein, between the output terminal of operational amplifier OP and negative input end, be parallel with the first resistance R 1 and the first capacitor C 1; The negative input end of operational amplifier OP is connected with one end of the second resistance R 2, and the other end of the second resistance R 2 is connected with one end of the second capacitor C 2; The other end of the second capacitor C 2 is connected with the power supply negative terminal of infrared eye (5); The positive input terminal of operational amplifier OP is connected with the output terminal of infrared sensor; The output terminal of operational amplifier OP is connected with analog to digital conversion circuit (72); The transition function of arrowband bandpass filtering amplifying circuit (71) is:
Figure 2014100942493100001DEST_PATH_IMAGE002
Regulate by the parameter to resistance R 1, R2, capacitor C 1, C2, realize arrowband bandpass filtering amplifying circuit (71) centre frequency f 0, bandwidth f w, enlargement factor A 0, quality factor q control.
5. a kind of infrared gas sensor according to claim 1, is characterized in that, the wick of light source (4) is tungsten filament or thermal resistance film; Under "on" position, light source (4) generates heat and produces infrared radiation;
Modulation of source driving circuit (74) is made up of light source (4), the 3rd resistance R 3, the 4th resistance R 4, the 5th resistance R 5, the 6th resistance R 6, triode VT1 and field effect transistor VT2; Wherein, the source electrode of field effect transistor VT2 connects power supply ground, the source electrode of field effect transistor VT2 is connected by the 6th resistance R 6 with the drain electrode of field effect transistor VT2, the drain electrode of field effect transistor VT2 connects the 5th resistance R 5, the gate pole of field effect transistor VT2 is connected with one end of the 4th resistance R 4, the emitter of triode VT1 respectively, the other end of the 4th resistance R 4 connects power supply VCC, triode VT1 collector is connected with the source electrode of field effect transistor VT2, the base stage of triode VT1 is connected with one end of the 3rd resistance R 3, and the other end of the 3rd resistance R 3 is connected with microprocessor (73); Between the other end of the 4th resistance R 4 and the other end of the 5th resistance R 5, be in series with light source (4); Be flow through successively light source (4), the 5th resistance R 5, the 6th resistance R 6 and field effect transistor VT2 of electric current that power supply VCC provides, realize the power supply to light source (4), the cyclic control signal that microprocessor (73) produces is successively through the 3rd resistance R 3, triode VT1 and field effect transistor VT2, and driving light source (4) periodically sends radiation light-wave;
Tungsten filament passes into current flow heats, temperature raise, along with the rising of temperature, tungsten filament resistance value increase, do not have electric current by time resistance be called cold resistance, in the time having electric current to pass through, resistance will raise, and be called thermal resistance; Tungsten filament cold resistance is very little, if light source (4) is lighted from cold resistance state, this process can produce very large dash current; Modulation of source driving circuit (74) is upper at light source (4) by loading certain electric current, has avoided light source (4) to light from cold resistance state;
When field effect transistor VT2 cut-off, power supply VCC arrives power supply ground through light source (4), resistance R 5, R6, can set by light source (4) current value by regulating resistance R6, determine light source (4) depth of modulation, when namely being on the scene effect pipe VT2 cut-off, light source passes into electric current in (4), while avoiding light source (4) cold resistance state to light, to the impact of power supply VCC;
Field effect transistor VT2 is the N-channel MOS FET of low on-resistance, conducting resistance only several ohm of zero points; When field effect transistor VT2 conducting, power supply VCC arrives power supply ground through light source (4), resistance R 5, field effect transistor VT2 and the leakage, source resistance R6 that are parallel to field effect transistor VT2, set by light source (4) current value by regulating resistance R5, determine the radiant light wave intensity that light source (4) produces;
Triode VT1 mono-is for the protection of field effect transistor VT2, prevents that field effect transistor VT2 from damaging, the 2nd, control signal and light source (4) the power supply VCC of microprocessor (73) output are isolated, and prevent phase mutual interference.
6. a kind of infrared gas sensor according to claim 2, is characterized in that, the wavelength coverage of infrared radiation is 2～5 μ m, 8～12 μ m, 2～12 μ m and 2～20 μ m.
7. adopt the detection method of infrared gas sensor as claimed in claim 1; It is characterized in that,
Measuring process one, initialization; Microprocessor (73) output cyclic control signal, described cyclic control signal is square wave, light source (4) just periodically sends radiation light-wave, the heat that radiation light-wave produces periodically heats gas indoor gas, impel gas indoor gas to carry out the circulation of " expand-shrink ", carry out sufficient gas exchange with environment, air chamber (9) is dried, is cleaned;
Measuring process two, signals collecting; Channel coding and the instruction of microprocessor (73) output sampled signal, gather and be converted to digital signal to temperature, each point voltage, infrared eye (5) output signal respectively; To each sensitive element output of infrared eye (5) through amplifying, filtered sine wave, after cyclic control signal makes in light source (4) electric current from large to small, carry out 128～1024 times and sample;
Measuring process three, calculates; To temperature, each point voltage, infrared eye (5) output, in the time that signals collecting is idle, calculate, concrete is at cyclic control signal, electric current in light source (4) to be calculated after changing from small to big; Wherein, in infrared eye (5), the output signal of each sensitive element is sinusoidal wave after arrowband bandpass filtering amplifying circuit (71) is processed, and samples, and calculate by following formula in a sine wave:
Figure 2014100942493100001DEST_PATH_IMAGE004
In formula, u mfor the analog sine measured value after gas absorption infrared energy to be measured, u rfor all gas to be measured does not all absorb the analog sine reference value after infrared energy, U mfor measured value u mpeak value, U rfor reference value u rpeak value, u m/ u rrepresenting the numerical value of a certain gas concentration to be measured, is the peakedness ratio of measured value and reference value sine function waveform, and n is sampling number in one-period, and the value of n is between 128～1024;
Measuring process four, self-inspection; Compare with the regime values of microprocessor (73) storage calculating the numerical value such as gained temperature, each point voltage, infrared eye (5) output, judge whether to exist fault, when fault, output fault type code;
Measuring process five, temperature compensation; Comprise zero temperature compensation and two steps of range temperature compensation to calculating the temperature compensation that the concentration parameter of gas carries out, obtain subsequently gas concentration value after temperature compensation;
Wherein, at real time temperature T ttime, the formula of zero temperature compensation is:
Figure 2014100942493100001DEST_PATH_IMAGE006
, in formula, k 0be zero temperature compensation coefficient, a is temperature T 0time be stored in the value in microprocessor (73) memory, a treal time temperature T ttime offset;
At real time temperature T ttime, the formula of range temperature compensation is:
, in formula, k srange temperature compensation coefficient, a treal time temperature T ttime offset, b is temperature T 0time be stored in the value in microprocessor (73) memory, u m/ u rreal time temperature T ttime measured value, c is the concentration value of the gas to be measured that will calculate after temperature compensated;
Measuring process six, converts the gas concentration value after the temperature compensation of step 5 to analog quantity or digital quantity signal, and transmits through interface (75).
8. adopt the detection method of infrared gas sensor as claimed in claim 7; It is characterized in that, before detecting, to the constant a and range constant b, zero temperature compensation coefficient k at zero point of infrared gas sensor 0with range temperature compensation coefficient k sdemarcate and deposit in microprocessor (73) memory, time to be measured, transfer and use; The method of concrete demarcation is carried out as follows:
Demarcating steps one, Zero calibration;
Infrared gas sensor is being demarcated temperature T 0under condition, in air chamber (9), pass into nitrogen, until air chamber (9) is full of nitrogen completely, measure the analog sine measured value u after the gas absorption infrared energy to be measured of each infrared sensor mall do not absorb the analog sine reference value u after infrared energy with gas to be measured r, and press formula
Figure 2014100942493100001DEST_PATH_IMAGE010
calculate the value of constant a at zero point, deposit in microprocessor (73) memory the temperature T that temperature sensor (6) measures in 0value also deposits in microprocessor (73) memory;
Demarcating steps two, range designation;
In the same temperature T of demarcating steps one 0time, in air chamber (9), pass into the Standard Gases sample that concentration is the gas to be measured of maximum range value, until air chamber (9) is full of the Standard Gases sample of this gas to be measured completely, measure the analog sine measured value u after the absorption infrared energy of each infrared sensor under the Standard Gases sample of this gas to be measured mwith under Standard Gases sample at this gas to be measured, do not absorb the analog sine reference value u after infrared energy rvalue, calculate the value of b by the formula of demarcating steps one, deposit in microprocessor (73) memory;
Demarcating steps three, zero temperature compensation coefficient is demarcated;
Make the environment temperature of temperature sensor (6) rise or drop to T t, again in air chamber (9), pass into nitrogen, until air chamber (9) is full of nitrogen completely, measures and calculate u m/ u rvalue, temperature is T ttime constant a at zero point tvalue, by the zero temperature compensation formula in measuring process five
Figure 924695DEST_PATH_IMAGE006
, calculate k 0value, deposits in microprocessor (73) memory;
Demarcating steps four, range temperature compensation coefficient is demarcated;
Continue the environment temperature of temperature sensor (6) to remain on T tunder state, be T toward passing into temperature in air chamber (9) t, concentration is the Standard Gases sample of the gas to be measured of maximum range value, measure and calculate u m/ u rvalue, by the range temperature compensation formula in measuring process five
Figure 593573DEST_PATH_IMAGE008
calculate k svalue and deposit in microprocessor (73) memory, time to be measured, call.
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Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104375073A (en) * 2014-11-18 2015-02-25 中国人民解放军63655部队 Photoelectric response sensitivity calibrating device for optical waveguide detector under different temperatures
CN105067554A (en) * 2015-09-10 2015-11-18 上海申渭电子科技有限公司 Infrared SF6 sensor device relevant to NDIR (Non-Dispersive Infrared Analyzer) and method
CN105486653A (en) * 2015-12-01 2016-04-13 昆明勤瑞科技有限公司 Sulfur dioxide infrared detection device and method
CN105938018A (en) * 2016-04-13 2016-09-14 电子科技大学 Pyroelectric detector
CN106442354A (en) * 2016-09-29 2017-02-22 湖北航天技术研究院总体设计所 Gas detecting device
CN108020521A (en) * 2016-10-28 2018-05-11 德尔格制造股份两合公司 Determine the device of the concentration of at least one of breathing gas mixture gas component
CN110023721A (en) * 2016-11-29 2019-07-16 森西欧有限公司 Integrated circuit sensor encapsulation and its manufacturing method
CN110361354A (en) * 2019-08-15 2019-10-22 深圳市诺安环境安全股份有限公司 More gas concentration detection apparatus and preparation method thereof, warning device
CN111033252A (en) * 2017-08-25 2020-04-17 周锦富 System and method for calibrating a gas detection device
CN112945890A (en) * 2021-02-03 2021-06-11 深圳市美思先端电子有限公司 Gas concentration detection device and control method thereof
CN113109516A (en) * 2021-04-21 2021-07-13 江南大学 Humidity sensor response and recovery time measuring device and method
CN113237843A (en) * 2021-01-19 2021-08-10 北立传感器技术（武汉）有限公司 Non-dispersive infrared gas analysis circuit and analysis method based on embedded system
CN116879215A (en) * 2023-07-18 2023-10-13 上海苏萨电子科技有限公司 Non-dispersive infrared gas sensor
CN116973521A (en) * 2023-09-21 2023-10-31 北京燕山时代仪表有限公司 Temperature compensation method and device for gas detector and gas detector

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS63113346A (en) * 1986-10-30 1988-05-18 Fujitsu Ltd Gas sensor
JPS63182550A (en) * 1987-01-23 1988-07-27 Fujitsu Ltd Gas sensor
EP0287929B1 (en) * 1987-04-24 1994-02-16 Miles Inc. Remote sensing gas analyzer
EP0681179A1 (en) * 1994-05-05 1995-11-08 Santa Barbara Research Center IR-based nitric oxide sensor having water vapor compensation
CN201222035Y (en) * 2008-06-18 2009-04-15 上海安誉智能科技有限公司 Detection sensor for infrared gas
CN100510713C (en) * 2007-02-01 2009-07-08 方剑德 Intelligent type infrared gas sensor
CN201909754U (en) * 2010-11-19 2011-07-27 上海翼捷工业安防技术有限公司 Optical gas sensor
WO2012059744A1 (en) * 2010-11-01 2012-05-10 Gas Sensing Solutions Ltd. Apparatus and method for generating light pulses from leds in optical absorption gas sensors
CN102495018A (en) * 2011-11-14 2012-06-13 济南火哨安全科技有限公司 Temperature compensation integrated infrared absorption gas sensor and detecting device

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS63113346A (en) * 1986-10-30 1988-05-18 Fujitsu Ltd Gas sensor
JPS63182550A (en) * 1987-01-23 1988-07-27 Fujitsu Ltd Gas sensor
EP0287929B1 (en) * 1987-04-24 1994-02-16 Miles Inc. Remote sensing gas analyzer
EP0681179A1 (en) * 1994-05-05 1995-11-08 Santa Barbara Research Center IR-based nitric oxide sensor having water vapor compensation
CN100510713C (en) * 2007-02-01 2009-07-08 方剑德 Intelligent type infrared gas sensor
CN201222035Y (en) * 2008-06-18 2009-04-15 上海安誉智能科技有限公司 Detection sensor for infrared gas
WO2012059744A1 (en) * 2010-11-01 2012-05-10 Gas Sensing Solutions Ltd. Apparatus and method for generating light pulses from leds in optical absorption gas sensors
CN201909754U (en) * 2010-11-19 2011-07-27 上海翼捷工业安防技术有限公司 Optical gas sensor
CN102495018A (en) * 2011-11-14 2012-06-13 济南火哨安全科技有限公司 Temperature compensation integrated infrared absorption gas sensor and detecting device

Non-Patent Citations (5)

* Cited by examiner, † Cited by third party
Title
GUANGJUN ZHANG 等: ""A miniaturized carbon dioxide gas sensor based on infrared absorption"", 《OPTICS AND LASERS IN ENGINEERING》 *
HAIQING ZHANG 等: ""Research on coal mine gas sensor systems based on near infrared spectrum"", 《PROCEDIA ENGINEERING》 *
刘永平 等: ""矿用红外气体传感器的结构及光学系统的设计与实现"", 《硅酸盐通报》 *
刘永平 等: ""矿用红外甲烷传感器的研制"", 《煤矿现代化》 *
程文楷 等: ""法国防爆型红外CO2检测仪的剖析"", 《煤炭科学技术》 *

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Publication number Priority date Publication date Assignee Title
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CN112945890B (en) * 2021-02-03 2024-06-04 深圳市美思先端电子有限公司 Gas concentration detection device and control method thereof
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CN116973521B (en) * 2023-09-21 2023-12-22 北京燕山时代仪表有限公司 Temperature compensation method and device for gas detector and gas detector

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