CN2237240Y - Infrared gas analysing instrument without gas room - Google Patents
Infrared gas analysing instrument without gas room Download PDFInfo
- Publication number
- CN2237240Y CN2237240Y CN 95206150 CN95206150U CN2237240Y CN 2237240 Y CN2237240 Y CN 2237240Y CN 95206150 CN95206150 CN 95206150 CN 95206150 U CN95206150 U CN 95206150U CN 2237240 Y CN2237240 Y CN 2237240Y
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- infrared
- gas
- light
- catoptron
- air chamber
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Abstract
The utility model relates to an infrared gas analyzing instrument for detecting the concentration of gas. The structure comprises a reflective mirror (2), a light source (1), a modulating disk (4) with a light hole (5), a light filtering piece (12), a detector (14), an active filter band-pass amplifier (15), a meter head (18), a motor (16), etc. according to a light path sequence. A reference signal generator is also arranged in an amplifying circuit. The utility model is mainly characterized in that the infrared gas analyzing instrument has no gas room, single light path and the light focusing detector (14); thus, the utility model has the advantages of simple structure, small volume, convenient use and manufacture, strong detection signal, high detection rate, wide and flat spectral response ranges, small temperature coefficient, multiple components, multiple functions, etc.
Description
The utility model relates to a kind of gas-detecting device, particularly relates to a kind of infrared gas analyzer.
The basic structure of common infrared gas analyzer comprises time double light path and how much various ways such as double light path, and they all contain air chamber.Closed window is equipped with at the two ends of air chamber, and the side has the air intake opening and the exhausr port of gas to be measured.With air pump gas to be measured is pumped into an air chamber.Gas to be measured or reference gas in infrared radiation (parallel infrared light) the transmission air chamber, device, amplifier detect and measure its concentration to gas to be measured after testing.Concrete a kind of infrared gas analyzer can be referring to Fig. 1.
Fig. 1 is the synoptic diagram of common a kind of how much double light path infrared gas analyzers.Among Fig. 1, the infrared light that is sent by light source 1 forms directional light through catoptron 2, sees through the analysis unthreaded hole 5 that has on light source window 3 and the chopper wheel 4 and is divided into two bundles with reference unthreaded hole 6, injects two air chambers respectively.One of them air chamber pumps into gas to be measured for analyzing air chamber 7 in it.Another air chamber is a reference air chamber 8, and interior dress does not have the fixed gas of absorption to infrared light, as nitrogen.The length of analyzing air chamber 7 and reference air chamber 8 is identical respectively with cross-sectional area.Analyze on the air chamber 7 and have gas access 9 and gas vent 10, gas to be measured is sent into by gas access 9 by external air pump and is analyzed air chamber 7.The two ends of air chamber are respectively by 11 sealings of air chamber window.Chopper wheel 4 is a disc, is driven by motor 16 and rotates.In chopper wheel 4 rotation processes, an end of analyzing air chamber 7 is aimed in forwarding to as directly over Fig. 1 during the position apart from an axle analysis unthreaded hole 5 far away on it just, and infrared directional light enters and analyzes air chamber 7 by analyzing unthreaded hole 5; And when position directly over 4 nearer reference unthreaded holes 6 of chopper wheel forward to as Fig. 1, aim at an end of reference air chamber 8 just, infrared directional light enters reference air chamber 8 by reference unthreaded hole 6.Because the periodic rotary of chopper wheel 4, make infrared directional light that same light source 1 sends respectively by two air chambers and modulate.Infrared directional light through two air chambers passes through optical filter 12 again, converges on the detecting device 14 through light cone 13.If when analyzing in the air chamber 7 no gas to be measured, then differently equate by the infrared energy behind two air chambers constantly, make that detecting device 14 output signals are zero; When in analyzing air chamber 7 gas to be measured being arranged, by the absorbed degree difference of the two-way infrared energy of two air chambers, two light signals that detecting device 14 receives vary in size, so the signal of output is non-vanishing.This signal is admitted in the amplifier 15, amplifies the back and is shown by gauge outfit.Because light signal is very weak, amplifier 15 uses lock-in amplifier usually, and the non-vanishing signal of being exported by detecting device 14 is directly proportional with the concentration of gas to be measured, thereby directly demonstrates the concentration value of gas on gauge outfit.
Existing this how much bifocal path structures that have air chamber can reduce signal drift and variation, have higher measuring accuracy.Exactly because but double light path, and air chamber and air pump are arranged, make the numerous and diverse volume of its structure bigger; Infrared directional light needs stronger light source; Simultaneously because catoptron 2 be the gold-plated making of metal material, and adopt complicated lock-in amplifier and light source and air chamber that window is all arranged, make the instrument costliness, use also inconvenience.
The purpose of this utility model just is to improve existing infrared gas analyzer bifocal path structure, designs no air chamber, monochromatic light road and adopts the gas analyzer of converging ray.Satisfying under the prerequisite of measuring accuracy, making infrared gas analyzer simple in structure, volume is little, and is cheap, more suitable.
No air chamber infrared gas analyzer of the present utility model, its structure includes catoptron by the front and back order of light path, be installed in the light source that can launch infrared light in the catoptron, have the chopper wheel of unthreaded hole, optical filter, detecting device, amplifier, the motor that gauge outfit and drive chopper wheel rotate etc.Because the utility model is a monochromatic light road form, so only have one group of unthreaded hole on the chopper wheel.Leave the space of one section opening between catoptron and optical filter, Infrared sees through gas to be measured in this space.In other words, the utility model does not have air chamber, does not use air pump, detects but instrument is placed in the environment of gas to be measured.Said catoptron is the concave mirror of ellipsoid or parabolic shape, and light source not necessarily is placed on the focus of catoptron, but the infrared light that the mirror reflects light source is sent behind unthreaded hole and optical filter on the chopper wheel, focuses on the detecting device.Said amplifier adopts the logical amplifying circuit of active power filtering band, also is provided with the reference signal generator in this amplifying circuit.Here the logical amplifying circuit of said band is better simply amplifying circuit, and the reference signal generator also is so, as utilizes voltage divider principle, produces a stable set potential, as reference potential.
Like this, the utility model has not had air chamber, is the monochromatic light road, and Infrared is not a directional light also, but focuses on the detecting device.The energy of the Infrared that detecting device receives is relevant with the existence and the concentration of the gas to be measured that Infrared sees through, and changes the energy signal of Infrared into electric signal, is referred to as detection signal.When (open space) in the light path no gas to be measured, detection signal equates that with reference signal in the amplifier amplifier output signal is zero; When (open space) in the light path when gas to be measured is arranged, detection signal is different and different with gas concentration, thereby reference signal is non-vanishing with the difference of detection signal, and proportional with the concentration of gas to be measured.The difference of two signals outputs to gauge outfit, as voltage table, is revealed, so measure the existence and the concentration of gas to be measured.
Fig. 1 provides the synoptic diagram of how much double light path infrared gas analyzers of prior art.
Fig. 2 provides the diagrammatic cross-section of no air chamber infrared gas analyzer of the present utility model.
1 is light source among Fig. 2, makes light source 1 send infrared radiation after the energising.2 is catoptron, is half ellipsoid or half the paraboloidal concave mirror that constitutes at metal-coated membrane on glass.After catoptron 2 reflections, infrared ray is assembled and is radiated on the detecting device 14.The straight-line segment that has arrow among Fig. 2 has provided the light path of infrared radiation.4 of chopper wheels have one group of unthreaded hole 5, and drive chopper wheel 4 rotations by motor 16 by gearing 19.Being installed in optical filter 12 on detecting device 14 terminations can have multiplely, selects variety classes optical filter 12, can detect existence and its concentration of variety classes gas.Detecting device 14 can be a pyroelectric detector, also can be photoelectricity (semiconductor) type detector.For example use detectors such as triglycine sulfate (TGS), lithium tantalate (LT), lithium niobate (LN), strontium barium niobate (SBN), lead titanates (PT), lead titanate-zirconate (PZT) or polymkeric substance; For example use mercury cadmium telluride (HgCdTe), lead selenide detectors such as (PbSe).Detecting device 14 produces a detection signal under the infrared radiation effect of assembling.Amplifier 15 adopts the logical amplifying circuit of active power filtering band, and it has filtering (frequency-selecting) and enlarging function simultaneously, for example high pass and low pass combinational circuit.Be provided with reference signal generation circuit in addition.The difference of reference signal and detection signal shows on gauge outfit 18 after amplifier 15 amplifies.
When selecting centre wavelength 4.64 μ m optical filters 12 for use, can survey the concentration of carbon monoxide (CO); When selecting centre wavelength 4.26 μ m optical filters 12 for use, can survey carbon dioxide (CO
2) concentration; When selecting centre wavelength 3.31 μ m optical filters 12 for use, can survey methane (CH
4) concentration; When selecting centre wavelength 3.1 μ m optical filters 12 for use, can survey acetylene (C
2H
2) concentration etc.
When using the utility model, as long as will there not be the environment that the air chamber infrared gas analyzer is put into gas to be measured, choose and adjust the optical filter 12 of corresponding gas to be measured, turn on the power switch, make light source 1 send infrared radiation and make 15 work of detecting device 14, amplifier, gauge outfit can be indicated the concentration of this kind gas.
The utlity model has following characteristics: (1) is placed directly in the gaseous environment and detects, thereby volume simple in structure is little because air pump is not used on no air chamber monochromatic light road, and cost easy to use is low.(2) because can not adopting directional light, the monochromatic light road utilizes ellipsoid or the parabolic shape catoptron converges to infrared radiation on the detecting device, strengthened detection signal, improved signal to noise ratio (S/N ratio), thereby can adopt the active power filtering bandpass amplifier, further made simple in structure reducing cost.(3) owing to adopt electrothermic type, photoelectricity (semiconductor) type detector, and have the detectivity height, advantage such as spectral response range is wide and smooth and temperature coefficient is little.(4) catoptron take in the polishing of metal-coated membrane on glass rather than metallic interior surface gold-plated, thereby not only be convenient to processing but also reduce cost.(5) can adopt multiple optical filter, same analyser carries out the detection of multicomponent gas.(6) this instrument also is provided with temperature sensor, for example thermistor; Humidity sensor, for example hygristor; Optical sensor, for example photoelectric cell.So also possessed measures ambient temperature, humidity and light intensity function simultaneously, can more convenient user use like this.
Claims (2)
1, a kind of no air chamber infrared gas analyzer, its structure is by the front and back order of light path, include catoptron (2), be installed in the light source that can launch infrared light (1) in the catoptron (2), the chopper wheel (4) that has unthreaded hole (5), optical filter (12), detecting device (14), amplifier (15), gauge outfit (18) and drive the motor (16) that chopper wheel (4) rotates, of the present utility model being characterised in that:
1. only have one group of unthreaded hole (5) on the chopper wheel (4);
2. leave the space of one section opening between catoptron (2) and optical filter (12), Infrared sees through gas to be measured in this space;
3. catoptron (2) is the concave mirror of ellipsoid or parabolic shape, the position that light source (1) is placed is not necessarily on the focus of catoptron (2), but make infrared light that light source (1) sends and by the infrared light of catoptron (2) reflection by unthreaded hole (5) and optical filter (12) on the chopper wheel (4) after, focus on the detecting device (14);
4. said amplifier (15) is the logical amplifying circuit of active power filtering band, also is provided with the reference signal generator in this amplifying circuit.
2, according to the described no air chamber infrared gas analyzer of claim 1, it is characterized in that said detecting device (14) is pyroelectric detector or photoelectricity (semiconductor) type detector, comprises mercury cadmium telluride (HgCdTe), lead selenide (PbSe), triglycine sulfate (TGS), lithium tantalate (LT), lithium niobate (LN), strontium barium niobate (SBN), lead titanates (PT), lead titanate-zirconate (PZT) or polymkeric substance detector.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 95206150 CN2237240Y (en) | 1995-04-03 | 1995-04-03 | Infrared gas analysing instrument without gas room |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 95206150 CN2237240Y (en) | 1995-04-03 | 1995-04-03 | Infrared gas analysing instrument without gas room |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN2237240Y true CN2237240Y (en) | 1996-10-09 |
Family
ID=33858163
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 95206150 Expired - Fee Related CN2237240Y (en) | 1995-04-03 | 1995-04-03 | Infrared gas analysing instrument without gas room |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN2237240Y (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100401136C (en) * | 2006-06-08 | 2008-07-09 | 中国科学院上海技术物理研究所 | Temp controllable modulator for space apparatus and method for preparing its modulating disk |
| CN100419408C (en) * | 2003-07-31 | 2008-09-17 | 索纪文 | Infrared-ray gas analyser |
| CN103808685A (en) * | 2012-11-14 | 2014-05-21 | 南京埃森环境技术有限公司 | Low-concentration flue gas infrared analyzer based on Fourier transform and detection method thereof |
| CN103868855A (en) * | 2014-03-27 | 2014-06-18 | 西安交通大学 | Light path deflection-based double-light-path single-sensor gas infrared detection system and method |
| CN107817219A (en) * | 2017-12-05 | 2018-03-20 | 北京国网富达科技发展有限责任公司 | A kind of twin-stage enhanced photo acoustic spectroscopic detector device and its detection method |
| CN107917888A (en) * | 2017-10-18 | 2018-04-17 | 上海虬祺传感器科技有限公司 | A kind of diffusion type non-dispersive infrared gas sensor |
-
1995
- 1995-04-03 CN CN 95206150 patent/CN2237240Y/en not_active Expired - Fee Related
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100419408C (en) * | 2003-07-31 | 2008-09-17 | 索纪文 | Infrared-ray gas analyser |
| CN100401136C (en) * | 2006-06-08 | 2008-07-09 | 中国科学院上海技术物理研究所 | Temp controllable modulator for space apparatus and method for preparing its modulating disk |
| CN103808685A (en) * | 2012-11-14 | 2014-05-21 | 南京埃森环境技术有限公司 | Low-concentration flue gas infrared analyzer based on Fourier transform and detection method thereof |
| CN103808685B (en) * | 2012-11-14 | 2016-09-07 | 南京埃森环境技术股份有限公司 | A kind of low-concentration flue gas infrared spectrum analyser based on Fourier transformation and detection method |
| CN103868855A (en) * | 2014-03-27 | 2014-06-18 | 西安交通大学 | Light path deflection-based double-light-path single-sensor gas infrared detection system and method |
| CN103868855B (en) * | 2014-03-27 | 2016-03-30 | 西安交通大学 | Based on Double-optical path single-sensor gas infrared detection system and the method for optical path-deflecting |
| CN107917888A (en) * | 2017-10-18 | 2018-04-17 | 上海虬祺传感器科技有限公司 | A kind of diffusion type non-dispersive infrared gas sensor |
| CN107817219A (en) * | 2017-12-05 | 2018-03-20 | 北京国网富达科技发展有限责任公司 | A kind of twin-stage enhanced photo acoustic spectroscopic detector device and its detection method |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C19 | Lapse of patent right due to non-payment of the annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |