CN2632670Y - Laser remote sensing gas detector - Google Patents
Laser remote sensing gas detector Download PDFInfo
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- CN2632670Y CN2632670Y CN 03268476 CN03268476U CN2632670Y CN 2632670 Y CN2632670 Y CN 2632670Y CN 03268476 CN03268476 CN 03268476 CN 03268476 U CN03268476 U CN 03268476U CN 2632670 Y CN2632670 Y CN 2632670Y
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Abstract
The utility model relate to a laser remote sensing gas detector, which comprises an outer cover and an internal circuit; wherein, the front end surface of the outer cover is fixedly provided with a lens with a unthreaded hole in the center, the focal distance position of the lens inside the outer cover is fixedly provided with a photo detector; the internal circuit comprises a diode laser emitting module, a sinus modulation signal generating circuit module and two phase sensitive circuit modules. The output terminals of the two phase sensitive circuit modules are connected with the signal processing and displaying circuits that take the CPU of a micro processor, and also are controlled by the signal processing and displaying circuits. Compared with the present gas detecting device, the utility model has the advantages of remote sensing detection, high sensitivity, fine real time performance, no poisoning situation of the sensing unit. Furthermore, resulting from that the used single laser source realizes the remote sensing detection to the methane gas and optimizes the structure of the detector as well as reduces the cost and make the optical remote sensing detecting methane gas technology reach the level of practicability.
Description
Technical field
The utility model relates to a kind of device of remote sensing gas concentration, is specially the laser remote sensing gas detector.
Background technology
At present, device or the equipment that is used to survey gas mainly contains:
The electrochemical process sniffer: the detected gas of input is by detecting electrode ionization, and the gas current of generation is proportional to and is detected gas concentration.Electrode carbon distribution or dust accumulation are bigger to the measurement result influence, and electrode life is shorter, is not suitable for long-term measurement.
Production by Catalytic Combustion Process sniffer: when detected gas contacts with the semiconductor gas sensing device with uniform temperature, because burning causes semiconductor gas sensing device temperature to change, this temperature variation will make electrical quantitys such as semiconductor gas sensing device resistance or voltage change, and can determine to be detected the concentration of gas thus.Major defect is easily " poisoning ", low-response, and selectivity is bad etc.
More than two kinds of devices all can not carry out remote sensing and detect.
The existing optical means of utilizing is carried out the device that gas remote sensing detects, and all adopts two lasing light emitters to produce dual wavelength and surveys light, and use mechanical chopper to carry out copped wave and handle.Owing to adopt two lasing light emitters and mechanical chopper, make the apparatus structure complexity, the cost costliness.
Summary of the invention
The utility model solves defective and the deficiency that existing gas boring and surveying device exists, particularly solving existing laser remote sensing gas boring and surveying device must adopt two lasing light emitter effects to survey light and the use apparatus structure complexity that mechanical chopper brought, the problem of cost costliness, provide a kind of and survey remote sensing gas boring and surveying device---the laser remote sensing gas detector of light, and be purpose only with the hardware configuration that this device is provided with single lasing light emitter effect.
Laser remote sensing gas detector described in the utility model is based on following detection principle: remove to modulate laser that diode laser with the centre frequency that is detected the gas absorption peak sends as surveying light with a sinusoidal signal of determining frequency, this detection light is penetrated by natural target materials such as corner reflector or metope anti-(loosing) after passing and being detected the zone, its anti-(loosing) penetrated light and is received device and receives and focus on and carry out photosignal conversion on the photodetector, the electric signal that conversion comes is carried out the detection of first harmonic signal and second harmonic signal respectively by two phase sensitive detectors, wherein the reference signal frequency of phase sensitive detector is consistent with the frequency of sinusoidal modulation signal, and (path-IC is C to be detected regional gas path-IC
RValue obtains the mean concentration of gas divided by detection range or light path R) will determine by following formula: C
R=K (P
2f/ P
1f), P here
2f, P
1fBe two phase sensitive detectors respectively detected return laser beams once with the power of second harmonic, K is determined by the calibration calibration experiments.
Based on above-mentioned principle, the utility model is to adopt following technical scheme to realize: the laser remote sensing gas detector, comprise housing and internal circuit, on the front end face of housing, be fixed with the lens that its center has unthreaded hole, the focal length place of lens is fixed with photodetector in housing, in internal circuit, comprise a diode laser transmitter module, the Laser emission outlet of diode laser transmitter module links to each other with conduction optical fiber, the other end of conduction optical fiber places in the unthreaded hole of lens center, in internal circuit, also comprise sinusoidal modulation signal generation circuit module, the signal output part of sinusoidal modulation signal generation circuit module links to each other with the modulation signal input port of diode laser transmitter module, internal circuit also comprises two phase sensitive detection circuit modules, the detection signal input end of each phase sensitive detection circuit module links to each other with the electrical signal of photodetector respectively, simultaneously, the input end of the reference frequency signal of each phase sensitive detection circuit module links to each other with the signal output part of sinusoidal modulation signal generation module respectively, the output terminal of two phase sensitive detection circuit modules be the signal Processing of core with the microprocessor CPU, display circuit links to each other and is subjected to this signal Processing, the control of display circuit.
Different tested gas has the centre frequency or the centre wavelength at known laser absorption peak.Be several centre wavelengths that often are detected the absorption peak of gas below: methane 1.653 μ m, carbon monoxide 1.581 μ m, carbon dioxide 1.580 μ m, ammonia 1.99 μ m.
Theoretically, the frequency of sinusoidal modulation signal does not exert an influence to the probe gas concentration result, but under the centre frequency at a certain gas absorption peak, the sinusoidal modulation signal of diode laser transmitter module modulation different frequency will influence the emission output power of diode laser transmitter module, and then influence the detection range of laser, therefore, under the definite situation of laser frequency (being generally centre frequency) at the absorption peak of difference gas to be measured, the frequency of sinusoidal modulation signal should guarantee the laser power maximum that the diode laser transmitter module is sent, to guarantee that maximum detection range is arranged.Because the laser diode of the different diode laser transmitter modules even the same model of same manufacturer production, its output power has great discreteness after the modulation sinusoidal signal, in the actual mechanical process, each diode laser transmitter module guarantees that the frequency of the maximum pairing sinusoidal modulation signal of its output power needs by debugging definite under certain laser frequency.
Laser remote sensing gas detector described in the utility model, because its laser emission part and each functional circuit have all adopted existing circuit module, each functional circuit module can be selected the product of different manufacturers, different model for use, but the function of each line end of each circuit module is known, therefore, the those of ordinary skill that how to connect between each module electricity field is known and need not creative work.With the microprocessor CPU is that the signal Processing of core, the computer hardware that display circuit is core in fact exactly make up with CPU, (in fact detected be the parameter relevant with first and second harmonic power to its course of work for the power signal of in good time gathering two detected return laser beam first and second harmonic waves of phase sensitive detection circuit, correlation parameter can calculate the ratio of two harmonic powers), under the support of corresponding computer software, calculate the ratio of two harmonic powers, finally obtain the concentration of tested gas with this, and concentration value is shown.The hardware circuitry of finishing above-mentioned functions is in computer technology highly developed today, the ordinary skill of computer realm be need not creative work can be finished, therefore, the utility model is not described in detail the concrete connection between the module (which line end which line end connects) and signal Processing, the concrete circuit connection structure of display circuit in the claims, but provided the physical circuit schematic diagram of signal Processing, display circuit in Figure of description.
The utility model is compared with existing gas boring and surveying device, and principal feature is to have realized remote sensing, and have highly sensitive, real-time good, can not produce sensing element " poisoning " phenomenon.Simultaneously,, optimized the structure of detector, reduced cost, made remote optical sensing survey the gas technology and reached practical degree owing to use the remote sensing of single lasing light emitter realization to methane gas.This detector also can be used for surveying the hazardous location or is not easy to install other harmful gas concentration in conventional detector zone.
Description of drawings
Fig. 1 is the structural representation of equipment of the present invention;
Fig. 2 is the synoptic diagram that line end connects between each circuit module in the equipment of the present invention;
Fig. 3 is the physical circuit schematic diagram of signal Processing, display circuit;
Fig. 4 is the signal Processing that is connected with Fig. 8, another part of display circuit;
Fig. 5 is apparatus casing figure;
Fig. 6 is apparatus casing rear panel structure figure;
Fig. 7 is apparatus casing front-panel structure figure;
Fig. 8 is used for coal mine gas monitoring synoptic diagram for the utility model;
Fig. 9 surveys synoptic diagram for the utility model is used for gas pipeline leakage;
Embodiment
The laser remote sensing gas detector, comprise housing 9 and internal circuit, on the front end face of housing 9, be fixed with the lens 4 that its center has unthreaded hole, the focal length place of lens 4 is fixed with photodetector 5 in housing, in internal circuit, comprise a diode laser transmitter module 2, the Laser emission outlet of diode laser transmitter module links to each other with conduction optical fiber 3, the other end of conduction optical fiber 3 places in the unthreaded hole at lens 4 centers, in internal circuit, also comprise sinusoidal modulation signal generation circuit module 1, the signal output part of sinusoidal modulation signal generation circuit module 1 links to each other with the modulation signal input port of diode laser transmitter module 2, internal circuit also comprises two phase sensitive detection circuit modules 6,7, the detection signal input end of each phase sensitive detection circuit module links to each other with the electrical signal of photodetector 5 respectively, simultaneously, the input end of the reference frequency signal of each phase sensitive detection circuit module links to each other with the signal output part of sinusoidal modulation signal generation module 1 respectively, two phase sensitive detection circuit modules 6,7 output terminal be the signal Processing of core with the microprocessor CPU, display circuit 8 links to each other and is subjected to this signal Processing, the control of display circuit.Lens are selected Fresnel Lenses for use; Stretch at optical fiber and connect a GRIN optical fiber collimator 10 on the end of lens unthreaded hole, an end of optical fiber collimator stretches in the lens unthreaded hole, makes emergent light vertical with the light plane of departure.
The G8605-23 that photodetector selects for use the loose company in Japanese shore to produce.IQ1A (1654-5) F2X46 that the diode laser transmitter module selects for use U.S. Power Technology company to produce, the LIA-BVD-150H that the phase sensitive detection circuit module selects for use German FEMTO company to produce, just have an optional grafting chip of modulation signal in the phase sensitive detection circuit module of this model, directly select for use this optional grafting chip of being plugged in the phase sensitive detection circuit module as the sinusoidal modulation signal generation circuit module in the internal circuit (this module is the SOM-1 that German FEMTO company produces).The centre wavelength of diode laser transmitter module is adjusted to 1.581 μ m (centre wavelength of the absorption peak of gas is 1.581 μ m).The diode laser transmitter module of this model is 10KHZ by debugging the frequency of determining sinusoidal modulation signal under this laser frequency, and amplitude is 1.2V.
Each phase sensitive detection circuit module of selecting for use has 32 pairs of inputs, output line terminal, two line ends of every centering are distinguished with A, C, like this, 32 couple input of each phase sensitive detection circuit module, output line terminal just are expressed as PinA1-PinA32 and PinC1-PinC32, at the back of each line end label mark-1 or-2, in order to distinguish the line end of two phase sensitive detection circuit modules.The line end PinA30 that has the phase sensitive detection circuit module of the optional grafting chip of modulation signal, PinA17 (being the signal output part of sinusoidal modulation signal generation circuit module 1) links to each other with the modulation signal input port of diode laser transmitter module 2, the line end PinA30 that has the phase sensitive detection circuit module of the optional grafting chip of modulation signal, PinA17 simultaneously with the reference frequency signal input end PinA32 of another phase sensitive detection circuit module, PinA31 links to each other, two phase sensitive detection circuit modules 6,7 output terminal PinA12-1, PinC15-1 and PinA12-2, PinC15-2 be the signal Processing of core with the microprocessor CPU, the respective end of display circuit 8 links to each other, and the detection signal input end PinC2-1 of each phase sensitive detection circuit module links to each other with the electrical signal of photodetector 5 respectively with PinC2-2.
The signal Processing, the display circuit 8 that with the microprocessor CPU are core comprise cpu chip (U1W78E58), transceiver (U2 74HCT245), latch (U3 74HCT573), storer (U4 62256), code translator (U5 74HCT138), interface extended chip (U6 8255), latch (U13 74HCT574), analog-digital converter (U12 ADC7874) and display (128X64LCD).On the P1.0-P1.5 of CPU line end, be connected with switch SW 1-SW6 respectively, switch SW 1-SW6 places on the rear panel of housing and corresponds respectively to the function of self check, calibration, single survey, tie-in, address+1, storage, be connected with the on-off circuit that comprises switch SW 0 at the RESET of CPU line end, switch SW 0 also places on the rear panel of housing and corresponding to power switch.The display screen of LCD places on the rear panel of housing, to show the concentration value of tested gas.Two phase sensitivity testing circuit modules output terminal PinA12-1, PinC15-1 link to each other with the respective end of analog-digital converter with PinA12-2, PinC15-2; The corresponding line end of interface extended chip links to each other with the corresponding line end of two phase sensitive detection circuit modules (corresponding relation has detailed demonstration in the accompanying drawings mutually), in order to the control to two phase sensitive detection circuit modules.
Under the control action of modulation signal, the diode laser module is sent the laser acquisition light of modulation, launch from the center unthreaded hole of lens through optical fiber and through laser aligner, laser radiation is to search coverage, and by natural target surfaces reflected back, converge to photoelectric commutator by receiver lens and carry out opto-electronic conversion, the electric signal after the conversion is together given two phase sensitive detection circuit modules together with modulation signal, demodulates first harmonic signal and second harmonic signal.These two signals obtain being detected the methane gas mean concentration in zone after being handled by the data processing display circuit, and show under the support according to computer software that aforementioned detection principle is worked out.
This detector can be used for coal mine gas monitoring (as shown in Figure 8); Also can be used for gas pipeline leakage and survey (as shown in Figure 9).
Claims (2)
1, a kind of laser remote sensing gas detector, comprise housing (9) and internal circuit, on the front end face of housing (9), be fixed with the lens (4) that its center has unthreaded hole, the focal length place of lens in housing (4) is fixed with photodetector (5), in internal circuit, comprise a diode laser transmitter module (2), the Laser emission outlet of diode laser transmitter module links to each other with conduction optical fiber (3), the other end of conduction optical fiber (3) places in the unthreaded hole at lens (4) center, it is characterized by: in internal circuit, also comprise sinusoidal modulation signal generation circuit module (1), the signal output part of sinusoidal modulation signal generation circuit module (1) links to each other with the modulation signal input port of diode laser transmitter module (2), internal circuit also comprises two phase sensitive detection circuit modules (6), (7), the detection signal input end of each phase sensitive detection circuit module links to each other with the electrical signal of photodetector (5) respectively, simultaneously, the input end of the reference frequency signal of each phase sensitive detection circuit module links to each other with the signal output part of sinusoidal modulation signal generation module (1) respectively, two phase sensitive detection circuit modules (6), (7) output terminal be the signal Processing of core with the microprocessor CPU, display circuit (8) links to each other and is subjected to this signal Processing, the control of display circuit.
2, laser remote sensing gas detector as claimed in claim 1, it is characterized by: the LIA-BVD-150H that the phase sensitive detection circuit module selects for use German FEMTO company to produce, just have an optional grafting chip of modulation signal in the phase sensitive detection circuit module of this model, directly select for use this optional grafting chip that is plugged in the phase sensitive detection circuit module as the sinusoidal modulation signal generation circuit module in the internal circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 03268476 CN2632670Y (en) | 2003-06-20 | 2003-06-20 | Laser remote sensing gas detector |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 03268476 CN2632670Y (en) | 2003-06-20 | 2003-06-20 | Laser remote sensing gas detector |
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| Publication Number | Publication Date |
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| CN2632670Y true CN2632670Y (en) | 2004-08-11 |
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| CN 03268476 Expired - Fee Related CN2632670Y (en) | 2003-06-20 | 2003-06-20 | Laser remote sensing gas detector |
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100510673C (en) * | 2005-07-30 | 2009-07-08 | 中国科学院安徽光学精密机械研究所 | Laser remote sensing delecting device for natural gas pipe line leakage and detection method thereof |
| CN106401650A (en) * | 2016-10-21 | 2017-02-15 | 中国矿业大学(北京) | Multi-parameter mine laneway fire monitoring and alarming system |
| CN106481361A (en) * | 2016-10-21 | 2017-03-08 | 中国矿业大学(北京) | Mine laneway fire monitoring alarm system |
| CN107246281A (en) * | 2016-10-21 | 2017-10-13 | 中国矿业大学(北京) | Mine self caused fire monitoring early-warning system |
| CN108387515A (en) * | 2017-02-03 | 2018-08-10 | 日本电产株式会社 | Appearance inspection device |
-
2003
- 2003-06-20 CN CN 03268476 patent/CN2632670Y/en not_active Expired - Fee Related
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100510673C (en) * | 2005-07-30 | 2009-07-08 | 中国科学院安徽光学精密机械研究所 | Laser remote sensing delecting device for natural gas pipe line leakage and detection method thereof |
| CN106401650A (en) * | 2016-10-21 | 2017-02-15 | 中国矿业大学(北京) | Multi-parameter mine laneway fire monitoring and alarming system |
| CN106481361A (en) * | 2016-10-21 | 2017-03-08 | 中国矿业大学(北京) | Mine laneway fire monitoring alarm system |
| CN107246281A (en) * | 2016-10-21 | 2017-10-13 | 中国矿业大学(北京) | Mine self caused fire monitoring early-warning system |
| CN108387515A (en) * | 2017-02-03 | 2018-08-10 | 日本电产株式会社 | Appearance inspection device |
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| 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 |