CN115015149B - Laser infrared gas concentration detection method and system based on dynamic absorption line - Google Patents

Laser infrared gas concentration detection method and system based on dynamic absorption line Download PDF

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CN115015149B
CN115015149B CN202210480618.7A CN202210480618A CN115015149B CN 115015149 B CN115015149 B CN 115015149B CN 202210480618 A CN202210480618 A CN 202210480618A CN 115015149 B CN115015149 B CN 115015149B
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voltage
absorption line
value
variable terminal
real
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CN115015149A (en
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陈海永
武传伟
张华杰
冯山虎
王婷
贾林涛
冉顺杰
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Hanwei Electronics Group Corp
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
    • G01N21/25—Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
    • G01N21/31—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
    • G01N21/35—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light
    • G01N21/3504—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light for analysing gases, e.g. multi-gas analysis
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/01—Arrangements or apparatus for facilitating the optical investigation
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/01—Arrangements or apparatus for facilitating the optical investigation
    • G01N2021/0106—General arrangement of respective parts
    • G01N2021/0112—Apparatus in one mechanical, optical or electronic block
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
    • Y02A50/20—Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters

Abstract

The invention provides a laser infrared gas concentration detection method and system based on a dynamic absorption line, wherein the method comprises the following steps: when the laser infrared gas concentration detection is carried out, the microprocessor reads a real-time environment temperature signal T outside the semiconductor laser, and determines an absorption line adjustment strategy according to the real-time environment temperature signal T: at the real-time environment temperature signal T < the switching temperature threshold T 1 Executing the 1 st absorption line strategy; at a switching temperature threshold T 1 The real-time environment temperature signal T is not less than the switching temperature threshold T 2 Executing the 2 nd absorption line strategy; and so on, at the switching temperature threshold T N‑2 The real-time environment temperature signal T is not less than the switching temperature threshold T N‑1 Executing an N-1 absorption line strategy; at the real-time environment temperature signal T > the switching temperature threshold T N‑1 When the nth absorption line policy is executed. The invention can rapidly and accurately detect whether the gas to be detected leaks or not in a severe environment.

Description

Laser infrared gas concentration detection method and system based on dynamic absorption line
Technical Field
The invention relates to the technical field of laser infrared gas detectors, in particular to a laser infrared gas concentration detection method and system based on a dynamic absorption line.
Background
Common combustible gas leakage detection methods include electrochemical methods, catalytic combustion methods, solid electrolyte methods, infrared spectrum absorption methods, and the like. The infrared spectrum is called as a fingerprint of a compound, has the advantages of high analysis speed, low cost, no consumption of samples, easy online measurement and the like, and the basic theoretical basis of the infrared spectrum absorption method is the lamberbi law.
It should be noted that in the technical field of laser infrared gas detectors, each gas molecule has a fixed absorption spectrum, and only when the central wavelength output by the semiconductor laser is tuned to the absorption peak of the gas to be detected, the light emitted by the semiconductor laser can be absorbed through the gas to be detected, and the concentration of the gas to be detected can be calculated by inversion through analysis of the change of the light intensity.
The tested gas comprises a plurality of gases such as methane, ethylene, propane, isobutane, chloromethane and the like; among them, the hydrocarbon mixture mainly composed of methane is a main component of natural gas. The natural gas reserves in China are rich, the distribution geographical environment is complex, and the natural gas pipeline leakage event is increased along with the perfection of gas pipelines such as east-west gas transportation, faithful Wu Xian, congnian blue and the like, the popularization and popularization of natural gas, and the extension of the pipeline operation time, but due to the aging of the pipeline, soil corrosion, stratum stress, construction damage and the like. Once the natural gas pipeline leaks, the safe and stable supply of urban basic energy can be seriously influenced, and the natural gas leaked into the atmosphere endangers ecological safety, and on the other hand, because of inflammable and explosive characteristics, the natural gas leakage can cause combustion and explosion, thereby seriously threatening personal safety of common people and causing huge property loss.
Because the gas leakage area of the natural gas pipeline is positioned in the dangerous environment of the industrial site, the detection personnel are inconvenient to directly contact in a short distance, and therefore, the combination of the infrared absorption spectrum gas sensing technology and the laser telemetry technology is necessary for detection. At present, the existing laser gas monitoring equipment adopts a fixed absorption line mode, and the using temperature range is generally-20 ℃ to 50 ℃; however, gas pipelines such as western gas east transport, faithful Wu Xian and trining blue are highly likely to be in severe environments such as extremely hot and extremely cold, and thus a system capable of rapidly and accurately detecting whether natural gas leaks in severe environments is highly demanded.
In order to solve the above problems, an ideal technical solution is always sought.
Disclosure of Invention
The invention aims at overcoming the defects of the prior art, and provides a laser infrared gas concentration detection method and system based on a dynamic absorption line.
In order to achieve the above purpose, the technical scheme adopted by the invention is as follows:
the first aspect of the invention provides a laser infrared gas concentration detection method based on a dynamic absorption line, which comprises the following steps:
before leaving the factory, calibrating the concentration under the N item target absorption lines according to the type of the gas to be tested and the type of the laser, and setting N-1 switching temperature thresholds corresponding to the N item target absorption lines;
When the laser infrared gas concentration detection is carried out, the microprocessor reads a real-time environment temperature signal T outside the semiconductor laser, and determines an absorption line adjustment strategy according to the real-time environment temperature signal T: at the real-time environment temperature signal T < the switching temperature threshold T 1 Executing the 1 st absorption line strategy; at a switching temperature threshold T 1 The real-time environment temperature signal T is not less than the switching temperature threshold T 2 Executing the 2 nd absorption line strategy; and so on, at the switching temperature threshold T N-2 The real-time environment temperature signal T is not less than the switching temperature threshold T N-1 Executing an N-1 absorption line strategy; at the real-time environment temperature signal T > the switching temperature threshold T N-1 Executing an Nth absorption line strategy;
each absorption line strategy comprises an adjustment rule I and an adjustment rule II; the target absorption lines corresponding to each absorption line strategy are different, and the target absorption lines under different regulation rules I correspond to different target voltage digital measuring value ranges;
when the ith absorption line strategy is executed, the laser modulation current is adjusted to be the modulation current I i And selectively starting the adjustment rule I and the adjustment rule II according to the input instruction until the output center wavelength of the semiconductor laser is adjusted to be within the center wavelength locking value interval W i The absorption line is adjusted to be the ith absorption line of the gas to be measured;
when the adjustment rule I is started, the microprocessor executes:
step A1, reading voltage value V of thermal sensitive resistor in laser RES And judging whether the condition is satisfied: digital voltage D DOWN Voltage value V less than or equal to RES Voltage digital quantity D less than or equal to up The method comprises the steps of carrying out a first treatment on the surface of the If not, turning to the step A2;
step A2, at the voltage value V RES < the digital value D of the voltage DOWN At a preset interval a 1 Variable terminal voltage V of dynamic increase temperature controller p Then, the increased variable terminal voltage V is judged p Whether or not it is smaller than the maximum value V of the variable terminal voltage pMAX If yes, turning to the step A1; if not, the voltage V at the increased variable terminal p = V pMAX And fixed end voltage V of temperature controller N ＞V NMIN At a preset interval a 2 Dynamic reduction of fixed end voltage V of temperature controller N And converting the step A1;
at the voltage value V RES > the voltage digital quantity D up At a preset interval a 3 Variable terminal voltage V of dynamic reduction temperature controller p Then, the reduced variable terminal voltage V is judged p Whether or not it is greater than the minimum value V of the variable terminal voltage pMIN If yes, turning to the step A1; if not, then the voltage V at the reduced variable terminal p = V pMIN And fixed end voltage V of temperature controller N ＜V NMAX At a preset interval a 4 Dynamic increase of fixed end voltage V of temperature controller N And converting the step A1;
When the adjustment rule II is started, the microprocessor executes:
step B1, reading the voltage value V of the thermistor in the laser RES And judging whether the condition is satisfied: digital voltage D TDOWN Voltage value V less than or equal to RES Voltage digital quantity D less than or equal to Tup If not, turning to the step B2;
step B2, at the voltage value V RES < the digital value D of the voltage TDOWN At a preset interval a 5 Variable terminal voltage V of dynamic increase temperature controller p Then, the increased variable terminal voltage V is judged p Whether or not to be smallAt maximum value V of variable terminal voltage pMAX If yes, turning to the step B1; if not, the voltage V at the increased variable terminal p =V pMAX And fixed end voltage V of temperature controller N ＞V NMIN At a preset interval a 6 Dynamic reduction of fixed end voltage V of temperature controller N And converting to step B1;
at the voltage value V RES > the voltage digital quantity D Tup At a preset interval a 7 Variable terminal voltage V of dynamic reduction temperature controller p Then, the reduced variable terminal voltage V is judged p Whether or not it is greater than the minimum value V of the variable terminal voltage pMIN If yes, turning to the step B1; if not, then the voltage V at the reduced variable terminal p =V pMIN And fixed end voltage V of temperature controller N ＜V NMAX At a preset interval a 8 Dynamic increase of fixed end voltage V of temperature controller N And converting to step B1..
The second aspect of the invention provides a laser infrared gas concentration detection system based on a dynamic absorption line, which comprises a preprocessing unit, an absorption line strategy management unit and an absorption line strategy execution unit, wherein the absorption line strategy execution unit comprises an execution unit I, an execution unit II and an execution unit III,
The pretreatment unit is used for calibrating the concentration under the N item target absorption lines according to the type of the gas to be tested and the type of the laser before leaving the factory, and setting N-1 switching temperature thresholds corresponding to the N item target absorption lines;
the absorption line strategy management unit is used for reading a real-time environment temperature signal T outside the semiconductor laser when the laser infrared gas concentration is detected, and determining an absorption line adjustment strategy according to the real-time environment temperature signal T: at the real-time environment temperature signal T < the switching temperature threshold T 1 Executing the 1 st absorption line strategy; at a switching temperature threshold T 1 The real-time environment temperature signal T is not less than the switching temperature threshold T 2 Executing the 2 nd absorption line strategy; and so on, at the switching temperature threshold T N-2 The real-time environment temperature signal T is not less than the switching temperature threshold T N-1 Executing an N-1 absorption line strategy; at the real-time environment temperature signal T > the switching temperature threshold T N-1 Executing an Nth absorption line strategy; each absorption line strategy comprises an adjustment rule I and an adjustment rule II; the target absorption lines corresponding to each absorption line strategy are different, and the target absorption lines under different regulation rules I correspond to different target voltage digital measuring value ranges;
The execution unit I is used for adjusting the laser modulation current to be modulation current I when executing the ith absorption line strategy i And selectively starting the adjustment rule I and the adjustment rule II according to the input instruction until the output center wavelength of the semiconductor laser is adjusted to be within the center wavelength locking value interval W i The absorption line is adjusted to be the ith absorption line of the gas to be measured;
the execution unit ii is configured to execute, when the adjustment rule i is enabled:
step A1, reading voltage value V of thermal sensitive resistor in laser RES And judging whether the condition is satisfied: digital voltage D DOWN Voltage value V less than or equal to RES Voltage digital quantity D less than or equal to up The method comprises the steps of carrying out a first treatment on the surface of the If not, turning to the step A2;
step A2, at the voltage value V RES < the digital value D of the voltage DOWN At a preset interval a 1 Variable terminal voltage V of dynamic increase temperature controller p Then, the increased variable terminal voltage V is judged p Whether or not it is smaller than the maximum value V of the variable terminal voltage pMAX If yes, turning to the step A1; if not, the voltage V at the increased variable terminal p = V pMAX And fixed end voltage V of temperature controller N ＞V NMIN At a preset interval a 2 Dynamic reduction of fixed end voltage V of temperature controller N And converting the step A1;
at the voltage value V RES > the voltage digital quantity D up At a preset interval a 3 Variable terminal voltage V of dynamic reduction temperature controller p Then, the reduced variable terminal voltage V is judged p Whether or not it is greater than the minimum value V of the variable terminal voltage pMIN If yes, turning to the step A1; if not, then the voltage V at the reduced variable terminal p = V pMIN And fixed end voltage V of temperature controller N ＜V NMAX At a preset interval a 4 Dynamic increase of fixed end voltage V of temperature controller N And converting the step A1;
the execution unit III is configured to execute, when the adjustment rule II is enabled:
step B1, reading the voltage value V of the thermistor in the laser RES And judging whether the condition is satisfied: digital voltage D TDOWN Voltage value V less than or equal to RES Voltage digital quantity D less than or equal to Tup If not, turning to the step B2;
step B2, at the voltage value V RES < the digital value D of the voltage TDOWN At a preset interval a 5 Variable terminal voltage V of dynamic increase temperature controller p Then, the increased variable terminal voltage V is judged p Whether or not it is smaller than the maximum value V of the variable terminal voltage pMAX If yes, turning to the step B1; if not, the voltage V at the increased variable terminal p =V pMAX And fixed end voltage V of temperature controller N ＞V NMIN At a preset interval a 6 Dynamic reduction of fixed end voltage V of temperature controller N And converting to step B1;
at the voltage value V RES > the voltage digital quantity D Tup At a preset interval a 7 Variable terminal voltage V of dynamic reduction temperature controller p Then, the reduced variable terminal voltage V is judged p Whether or not it is greater than the minimum value V of the variable terminal voltage pMIN If yes, turning to the step B1; if not, then the voltage V at the reduced variable terminal p =V pMIN And fixed end voltage V of temperature controller N ＜V NMAX At a preset interval a 8 Dynamic increase of fixed end voltage V of temperature controller N And converting to step B1.
A third aspect of the present invention provides a dynamic absorption line-based laser infrared gas concentration detection apparatus comprising a memory, a processor, and a dynamic absorption line-based laser infrared gas concentration detection program stored on the memory and operable on the processor, which when executed by the processor, implements the steps of the dynamic absorption line-based laser infrared gas concentration detection method as described above.
A fourth aspect of the present invention provides a readable storage medium having stored thereon instructions which, when executed by a processor, implement the steps of a laser infrared gas concentration detection method based on a dynamic absorption line as described above.
Compared with the prior art, the invention has outstanding substantive characteristics and remarkable progress, and concretely comprises the following steps:
1) In the invention, in an industrial field, a microprocessor automatically and dynamically adjusts an absorption line strategy according to a real-time environment temperature signal T outside a semiconductor laser so as to match the absorption line of a changed laser infrared gas concentration detection system with the field environment; after determining what absorption line strategy to execute, the microprocessor also selectively enables the adjustment rule I and the adjustment rule II based on the input instruction, and the real-time voltage value V of the thermistor in the semiconductor laser RES Variable terminal voltage and fixed terminal voltage V of dynamic temperature controller N Thereby detecting the existence of the gas to be detected in the severe environment rapidly and accurately;
2) After confirming that the execution of the adjustment rule I is finished, the microprocessor also detects whether the absorption line adjustment is successful, and when the voltage digital value range corresponding to the adjustment rule I in the ith absorption line strategy is matched with the real-time voltage digital value range, the microprocessor judges that the absorption line adjustment is successful and can continue to calculate and generate the current concentration of the gas to be measured; if the gas to be measured is not matched with the gas to be measured, judging that the adjustment of the absorption line fails, and generating a first feedback message without continuously calculating the current concentration of the gas to be measured;
3) After confirming the execution of the adjustment rule II, the microprocessor also detects whether the absorption line adjustment is successful, and the absorption line adjustment is performed at the real-time center wavelength W' i Center wavelength lock value interval W corresponding to adjustment rule II in ith absorption line strategy i When matching, judging that the absorption line is successfully adjusted, and continuously calculating to generate the current concentration of the gas to be detected; if the gas concentration is not matched with the current concentration, judging that the absorption line adjustment fails, and generating a second feedback without continuously calculating the current concentration of the gas to be detectedA message.
Drawings
FIG. 1 is a flow chart of a method for detecting laser infrared gas concentration based on dynamic absorption lines according to the present invention;
FIG. 2 is a flow chart II of the laser infrared gas concentration detection method based on dynamic absorption lines of the present invention;
FIG. 3 is a flow chart of the dynamic adjustment of reference voltage temperature control under a fixed absorption line based on a reference air chamber of the present invention;
FIG. 4 is a flow chart of the dynamic adjustment of reference voltage temperature control under fixed absorption without a reference air chamber of the present invention;
fig. 5 is a schematic structural diagram of a semiconductor laser.
Detailed Description
The technical scheme of the invention is further described in detail through the following specific embodiments.
The laser gas detection is based on molecular spectrum theory, different molecules have unique absorption lines, and the lines have strong, widened, linear and other parameters and depend on pressure and temperature changes. The selection of proper detection spectral lines and spectral line parameters is a precondition for gas detection, the near infrared spectrum covers a very wide spectral range, and has a very large number of absorption lines (absorption lines), each gas has a respective absorption peak, is easy to distinguish, and is most widely used in the field of gas detection.
As shown in fig. 5, the semiconductor laser 2 and the thermistor 3 are positioned in the constant temperature cavity 1, and the temperature controller (TEC driver) 4, the microprocessor 5 and the temperature sensor 6 are positioned outside the constant temperature cavity 1;
One end of the thermistor 3 is connected with an RT+ pin of the semiconductor laser 2, and the other end of the thermistor 3 is connected with the microprocessor 5 and is used for collecting temperature signals in the constant temperature cavity 1 in real time and transmitting the temperature signals to the microprocessor 5; a first terminal of the TEC driving unit 4 is connected with a tec+ pin of the semiconductor laser 2, a second terminal of the TEC driving unit 4 is connected with a TEC-pin of the semiconductor laser 2, and a third terminal of the TEC driving unit 4 is connected with the microprocessor 5 and is used for receiving an adjusting instruction of the microprocessor 5 so as to adjust the output power of the TEC driving unit 4 and further change the temperature in the constant-temperature cavity 1; the temperature sensor 6 is connected with the microprocessor 5, and is used for collecting temperature signals (the current environmental temperature T of the equipment) outside the constant temperature cavity 1 in real time and transmitting the temperature signals to the microprocessor 5.
Example 1
A method for detecting laser infrared gas concentration based on dynamic absorption lines, the method comprising the steps of:
before leaving the factory, calibrating the concentration under the N item target absorption lines according to the type of the gas to be tested and the type of the laser, and setting N-1 switching temperature thresholds corresponding to the N item target absorption lines;
When the laser infrared gas concentration detection is carried out, the microprocessor reads a real-time environment temperature signal T outside the semiconductor laser, and determines an absorption line adjustment strategy according to the real-time environment temperature signal T: at the real-time environment temperature signal T < the switching temperature threshold T 1 Executing the 1 st absorption line strategy; at a switching temperature threshold T 1 The real-time environment temperature signal T is not less than the switching temperature threshold T 2 Executing the 2 nd absorption line strategy; and so on, at the switching temperature threshold T N-2 The real-time environment temperature signal T is not less than the switching temperature threshold T N-1 Executing an N-1 absorption line strategy; at the real-time environment temperature signal T > the switching temperature threshold T N-1 Executing an Nth absorption line strategy;
each absorption line strategy comprises an adjustment rule I and an adjustment rule II; the target absorption lines corresponding to each absorption line strategy are different, and the target absorption lines under different regulation rules I correspond to different target voltage digital measuring value ranges;
when the ith absorption line strategy is executed, the laser modulation current is adjusted to be the modulation current I i And selectively starting the adjustment rule I and the adjustment rule II according to the input instruction until the output center wavelength of the semiconductor laser is adjusted to be within the center wavelength locking value interval W i In which the absorption line is adjusted to the ith absorption line of the gas to be measured；
When the adjustment rule I is started, the microprocessor executes:
step A1, reading voltage value V of thermal sensitive resistor in laser RES And judging whether the condition is satisfied: digital voltage D DOWN Voltage value V less than or equal to RES Voltage digital quantity D less than or equal to up The method comprises the steps of carrying out a first treatment on the surface of the If not, turning to the step A2;
step A2, at the voltage value V RES < the digital value D of the voltage DOWN At a preset interval a 1 Variable terminal voltage V of dynamic increase temperature controller p Then, the increased variable terminal voltage V is judged p Whether or not it is smaller than the maximum value V of the variable terminal voltage pMAX If yes, turning to the step A1; if not, the voltage V at the increased variable terminal p = V pMAX And fixed end voltage V of temperature controller N ＞V NMIN At a preset interval a 2 Dynamic reduction of fixed end voltage V of temperature controller N And converting the step A1;
at the voltage value V RES > the voltage digital quantity D up At a preset interval a 3 Variable terminal voltage V of dynamic reduction temperature controller p Then, the reduced variable terminal voltage V is judged p Whether or not it is greater than the minimum value V of the variable terminal voltage pMIN If yes, turning to the step A1; if not, then the voltage V at the reduced variable terminal p = V pMIN And fixed end voltage V of temperature controller N ＜V NMAX At a preset interval a 4 Dynamic increase of fixed end voltage V of temperature controller N And converting the step A1;
When the adjustment rule II is started, the microprocessor executes:
step B1, reading the voltage value V of the thermistor in the laser RES And judging whether the condition is satisfied: digital voltage D TDOWN Voltage value V less than or equal to RES Voltage digital quantity D less than or equal to Tup If not, turning to the step B2;
step B2, at the voltage value V RES < the digital value D of the voltage TDOWN At a preset interval a 5 Variable terminal voltage V of dynamic increase temperature controller p After that, judge to increasePost variable terminal voltage V p Whether or not it is smaller than the maximum value V of the variable terminal voltage pMAX If yes, turning to the step B1; if not, the voltage V at the increased variable terminal p =V pMAX And fixed end voltage V of temperature controller N ＞V NMIN At a preset interval a 6 Dynamic reduction of fixed end voltage V of temperature controller N And converting to step B1;
at the voltage value V RES > the voltage digital quantity D Tup At a preset interval a 7 Variable terminal voltage V of dynamic reduction temperature controller p Then, the reduced variable terminal voltage V is judged p Whether or not it is greater than the minimum value V of the variable terminal voltage pMIN If yes, turning to the step B1; if not, then the voltage V at the reduced variable terminal p =V pMIN And fixed end voltage V of temperature controller N ＜V NMAX At a preset interval a 8 Dynamic increase of fixed end voltage V of temperature controller N And converting to step B1.
Wherein, the variable terminal voltage V of the temperature controller p The initial value of the fixed end voltage of the thermostat is set to V0.
Specifically, the voltage digital quantity D in the step A1 DOWN And a digital value D of voltage up Is arranged in one-to-one correspondence with the regulation rule I, and the regulation rule I under different absorption line strategies corresponds to different voltage digital quantities D DOWN And a digital value D of voltage up The method comprises the steps of carrying out a first treatment on the surface of the Before leaving factory, the absorption line strategy, the regulation rule I and the voltage digital quantity D are configured DOWN And a digital value D of voltage up The mapping relation between the two is stored in a storage module in advance;
the voltage digital quantity D in the step B1 TDOWN And a digital value D of voltage Tup The voltage digital quantity D is set in one-to-one correspondence with the regulation rule II, and the regulation rule II under different absorption line strategies corresponds to different voltage digital quantities D TDOWN And a digital value D of voltage Tup The method comprises the steps of carrying out a first treatment on the surface of the Before leaving factory, the absorption line strategy, the regulation rule II and the voltage digital quantity D are configured TDOWN And a digital value D of voltage Tup The mapping relation between the two is stored in the storage module in advance.
In order to further improve the detection precision and ensure low power consumption, the embodiment also detects whether the absorption line adjustment is successful, and when the absorption line adjustment is judged to be successful, the concentration of the gas to be detected is continuously calculated, wherein the calculation mode is the prior art and is not repeated here; when it is determined that the absorption line adjustment fails, calculation is not continued, the gas concentration is not outputted, or even if the gas concentration is outputted, it is necessary to mark the gas concentration, which is described for rough reference.
Further, after confirming that the execution of the adjustment rule i is completed, the microprocessor further detects whether the absorption line adjustment is successful:
extracting the second harmonic of the reference gas circuit signal to obtain the maximum value of the second harmonic of the reference gas circuit signal;
extracting a real-time voltage digital value measuring range according to a mapping relation between a pre-stored second harmonic maximum value and the voltage digital value measuring range;
judging whether a voltage digital measuring value range corresponding to an adjusting rule I in an ith absorption line strategy is matched with the real-time voltage digital measuring value range, if not, judging that the absorption line adjustment fails, and generating a first feedback message.
Further, after confirming that the execution of the adjustment rule ii is completed, the microprocessor further detects whether the absorption line adjustment is successful:
reading the real-time center wavelength W 'of the output of a semiconductor laser' i Judging the real-time center wavelength W' i Center wavelength lock value interval W corresponding to adjustment rule ii in the ith absorption line policy i If the absorption line is matched, judging that the absorption line adjustment fails, and generating a second feedback message.
It should be noted that, different molecules have infrared spectra with different frequencies, which is the basis for judging the molecular types of different gases; therefore, in order to solve the problem of monitoring various gas types such as methane, ethylene, propane, isobutane, chloromethane and the like, the invention sets a polling mechanism, sequentially calls switching temperature thresholds corresponding to different gas types such as methane, ethylene, propane, isobutane, chloromethane and the like according to a preset sequence in one detection period, and determines an absorption line adjustment strategy according to the relation between the called switching temperature thresholds and a real-time environment temperature signal T.
In one embodiment, taking a semiconductor near infrared laser with a type of CH4 and a type of laser as an example, two absorption lines are set, and a first absorption line of the gas to be measured is configured as a 1651nm switching temperature threshold T 1 The second absorption line of the gas to be measured is arranged to be 1654nm, and the temperature threshold T is switched 1 35 ℃; as shown in figure 2, the ambient temperature signal T outside the cavity is less than the switching temperature threshold T 1 When the method is used, the 1 st absorption line strategy is executed, and the absorption line of the laser infrared gas concentration detection system is adjusted to be a first absorption line of the gas to be detected; the ambient temperature signal T outside the cavity is more than or equal to the switching temperature threshold T 1 And executing the 2 nd absorption line strategy, wherein the absorption line of the laser infrared gas concentration detection system is adjusted to be the second absorption line of the gas to be detected.
Specifically, the interval a 1 Said interval a 2 Said interval a 3 Said interval a 4 Said interval a 5 Said interval a 6 Said interval a 7 And the interval a 8 The steps are the same and are all 0.01V to 0.5V, for example, 0.01V,0.05V, 0.15V or 0.25, etc., and can be modified according to actual requirements.
The interval a can be adjusted according to actual requirements 1 Said interval a 2 Said interval a 3 Said interval a 4 Said interval a 5 Said interval a 6 Said interval a 7 And the interval a 8 The method ensures that the central wavelength change ranges of the lasers corresponding to the two absorption lines of the CH4 after the absorption lines are adjusted are not crossed, and further improves the detection precision.
In a specific embodiment, taking a gas type to be detected as CH4 and a laser type as a semiconductor mid-infrared laser as an example, three absorption lines are set; as shown in figure 1, the microprocessor reads the semiconductor laser when detecting the concentration of the laser infrared gasAn external real-time environment temperature signal T, and determining an absorption line adjustment strategy according to the real-time environment temperature signal T: at the real-time environment temperature signal T < the switching temperature threshold T 1 Executing the 1 st absorption line strategy; at a switching temperature threshold T 1 The real-time environment temperature signal T is not less than the switching temperature threshold T 2 Executing the 2 nd absorption line strategy; at the real-time environment temperature signal T > the switching temperature threshold T 2 At that time, the 3 rd absorption line policy is executed.
It should be noted that, the number of the target absorption lines is N, the number of the switching temperature thresholds is N-1, and the number of the absorption line strategies is N; the above two embodiments are examples, and in practical applications, the number of absorption lines to be targeted may be set according to the type of gas to be measured and the type of laser.
Example 2
The embodiment provides a laser infrared gas concentration detection system based on a dynamic absorption line, which comprises a preprocessing unit, an absorption line strategy management unit and an absorption line strategy execution unit, wherein the absorption line strategy execution unit comprises an execution unit I, an execution unit II and an execution unit III,
the pretreatment unit is used for calibrating the concentration under the N item target absorption lines according to the type of the gas to be tested and the type of the laser before leaving the factory, and setting N-1 switching temperature thresholds corresponding to the N item target absorption lines;
the absorption line strategy management unit is used for reading a real-time environment temperature signal T outside the semiconductor laser when the laser infrared gas concentration is detected, and determining an absorption line adjustment strategy according to the real-time environment temperature signal T: at the real-time environment temperature signal T < the switching temperature threshold T 1 Executing the 1 st absorption line strategy; at a switching temperature threshold T 1 The real-time environment temperature signal T is not less than the switching temperature threshold T 2 Executing the 2 nd absorption line strategy; and so on, at the switching temperature threshold T N-2 The real-time environment temperature signal T is not less than the switching temperature threshold T N-1 Executing an N-1 absorption line strategy; at the real-time ambient temperature signal T > switching temperature Threshold T N-1 Executing an Nth absorption line strategy; each absorption line strategy comprises an adjustment rule I and an adjustment rule II; the target absorption lines corresponding to each absorption line strategy are different, and the target absorption lines under different regulation rules I correspond to different target voltage digital measuring value ranges;
the execution unit I is used for adjusting the laser modulation current to be modulation current I when executing the ith absorption line strategy i And selectively starting the adjustment rule I and the adjustment rule II according to the input instruction until the output center wavelength of the semiconductor laser is adjusted to be within the center wavelength locking value interval W i The absorption line is adjusted to be the ith absorption line of the gas to be measured;
the execution unit ii is configured to execute, when the adjustment rule i is enabled:
step A1, reading voltage value V of thermal sensitive resistor in laser RES And judging whether the condition is satisfied: digital voltage D DOWN Voltage value V less than or equal to RES Voltage digital quantity D less than or equal to up The method comprises the steps of carrying out a first treatment on the surface of the If not, turning to the step A2;
step A2, at the voltage value V RES < the digital value D of the voltage DOWN At a preset interval a 1 Variable terminal voltage V of dynamic increase temperature controller p Then, the increased variable terminal voltage V is judged p Whether or not it is smaller than the maximum value V of the variable terminal voltage pMAX If yes, turning to the step A1; if not, the voltage V at the increased variable terminal p = V pMAX And fixed end voltage V of temperature controller N ＞V NMIN At a preset interval a 2 Dynamic reduction of fixed end voltage V of temperature controller N And converting the step A1;
at the voltage value V RES > the voltage digital quantity D up At a preset interval a 3 Variable terminal voltage V of dynamic reduction temperature controller p Then, the reduced variable terminal voltage V is judged p Whether or not it is greater than the minimum value V of the variable terminal voltage pMIN If yes, turning to the step A1; if not, then the voltage V at the reduced variable terminal p = V pMIN And fixed end voltage V of temperature controller N ＜V NMAX At a preset interval a 4 Dynamic increase of fixed end voltage V of temperature controller N And converting the step A1;
the execution unit III is configured to execute, when the adjustment rule II is enabled:
step B1, reading the voltage value V of the thermistor in the laser RES And judging whether the condition is satisfied: digital voltage D TDOWN Voltage value V less than or equal to RES Voltage digital quantity D less than or equal to Tup If not, turning to the step B2;
step B2, at the voltage value V RES < the digital value D of the voltage TDOWN At a preset interval a 5 Variable terminal voltage V of dynamic increase temperature controller p Then, the increased variable terminal voltage V is judged p Whether or not it is smaller than the maximum value V of the variable terminal voltage pMAX If yes, turning to the step B1; if not, the voltage V at the increased variable terminal p =V pMAX And fixed end voltage V of temperature controller N ＞V NMIN At a preset interval a 6 Dynamic reduction of fixed end voltage V of temperature controller N And converting to step B1;
at the voltage value V RES > the voltage digital quantity D Tup At a preset interval a 7 Variable terminal voltage V of dynamic reduction temperature controller p Then, the reduced variable terminal voltage V is judged p Whether or not it is greater than the minimum value V of the variable terminal voltage pMIN If yes, turning to the step B1; if not, then the voltage V at the reduced variable terminal p =V pMIN And fixed end voltage V of temperature controller N ＜V NMAX At a preset interval a 8 Dynamic increase of fixed end voltage V of temperature controller N And converting to step B1.
Further, the laser infrared gas concentration detection system based on the dynamic absorption line is characterized by further comprising an absorption line adjustment confirmation unit I, which is used for:
after confirming that the execution of the adjustment rule I is finished, extracting the second harmonic of the reference gas path signal to obtain the maximum value of the second harmonic of the reference gas path signal;
extracting a real-time voltage digital value measuring range according to a mapping relation between a pre-stored second harmonic maximum value and the voltage digital value measuring range;
judging whether a voltage digital measuring value range corresponding to an adjusting rule I in an ith absorption line strategy is matched with the real-time voltage digital measuring value range, if not, judging that the absorption line adjustment fails, and generating a first feedback message.
Further, the laser infrared gas concentration detection system based on the dynamic absorption line is characterized by further comprising an absorption line adjustment confirmation unit II, which is used for:
after confirming that the execution of the adjustment rule II is finished, reading the real-time center wavelength W 'output by the semiconductor laser' i Judging the real-time center wavelength W' i Center wavelength lock value interval W corresponding to adjustment rule ii in the ith absorption line policy i If the absorption line is matched, judging that the absorption line adjustment fails, and generating a second feedback message.
The laser temperature control method is generally that the voltage at one end of a fixed temperature controller (TEC driver) 4, for example, the TEC-pin of the temperature controller (TEC driver) is a fixed voltage of 2.5V after passing through a voltage dividing resistor; in addition, the voltage at the other end of the temperature controller (TEC driver) 4 is limited in voltage range, for example, the maximum voltage of 3.3V can be loaded on a TEC+ pin of the temperature controller (TEC driver), and the TEC driving mode has the defects that the voltage and current output between TEC+ and TEC-are limited in variable range and cannot be output greatly, so that the output power of the TEC driver is limited, and the temperature control of a laser is affected. Therefore, the invention combines the laser temperature control method for dynamically adjusting the reference voltage on the basis of changing the absorption line, thereby realizing the rapid and accurate detection of whether the natural gas leaks in the severe environment and having the advantage of reducing the power consumption of the laser.
The principle of laser temperature control for dynamically adjusting reference voltage is as follows: after changing the absorption line, keeping the absorption line unchanged; under normal circumstances, the TEC-pin of the temperature controller (TEC driver) 4 outputs a reference voltage (fixed end voltage V) by default through DAC N ) Changing the voltage of TEC+ pin of TEC driverDAC0 (fixed end voltage V) N ) The TEC+ pin voltage of the TEC driver is changed, so that the temperature control of the laser is realized; when a severe environment or place is met, such as extremely cold or extremely hot environment, the voltage of the TEC-pin loaded on the temperature controller (TEC driver) 4 is changed step by step, and the voltage of the TEC+ pin of the temperature controller (TEC driver) is combined to change, so that the temperature control of the wide temperature of the laser is realized.
Example 3
The embodiment provides a specific implementation manner of a dynamic absorption line-based laser infrared gas concentration detection device, which comprises a memory, a processor and a dynamic absorption line-based laser infrared gas concentration detection program stored on the memory and capable of running on the processor, wherein the dynamic absorption line-based laser infrared gas concentration detection program realizes the steps of the dynamic absorption line-based laser infrared gas concentration detection method as in embodiment 1 when being executed by the processor.
The present embodiment also provides a specific implementation of a readable storage medium, on which instructions are stored, which when executed by a processor implement the steps of the dynamic absorption line-based laser infrared gas concentration detection method as in embodiment 1.
In the foregoing embodiments, the descriptions of the embodiments are emphasized, and in part, not described or illustrated in any particular embodiment, reference is made to the related descriptions of other embodiments.
Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.
In the embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other manners. For example, the above-described apparatus embodiments are merely illustrative, and for example, the above-described division of modules is merely a logical function division, and there may be additional divisions when actually implemented, for example, multiple units or components may be combined or integrated into another system, or some features may be omitted or not performed.
In addition, each functional unit in the embodiments of the present application may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit. The integrated units may be implemented in hardware or in software functional units.
The integrated modules described above, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the present application may implement all or part of the flow of the method of the above embodiment, or may be implemented by a computer program to instruct related hardware, where the computer program may be stored in a computer readable storage medium, and when the computer program is executed by a processor, the steps of each method embodiment may be implemented. The computer program comprises computer program code, and the computer program code can be in a source code form, an object code form, an executable file or some intermediate form and the like.
Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present application and not for limiting the same; while the application has been described in detail with reference to the preferred embodiments, those skilled in the art will appreciate that: modifications may be made to the specific embodiments of the present application or equivalents may be substituted for part of the technical features thereof; without departing from the spirit of the application, it is intended to cover the scope of the application as claimed.

Claims (8)

1. The laser infrared gas concentration detection method based on the dynamic absorption line is characterized by comprising the following steps of:
before leaving the factory, calibrating the concentration under the N item target absorption lines according to the type of the gas to be tested and the type of the laser, and setting N-1 switching temperature thresholds corresponding to the N item target absorption lines;
when the laser infrared gas concentration detection is carried out, the microprocessor reads a real-time environment temperature signal T outside the semiconductor laser, and determines an absorption line adjustment strategy according to the real-time environment temperature signal T:
if n=2, then the real-time ambient temperature signal T < the switching temperature threshold T 1 Executing the 1 st absorption line strategy; at the time that the real-time environment temperature signal T is more than or equal to the switching temperature threshold T 1 Executing the 2 nd absorption line strategy;
if n=3, then the real-time ambient temperature signal T < the switching temperature threshold T 1 Executing the 1 st absorption line strategy; at a switching temperature threshold T 1 The real-time environment temperature signal T is not less than the switching temperature threshold T 2 Executing the 2 nd absorption line strategy; at the real-time environment temperature signal T > the switching temperature threshold T 2 Executing a 3 rd absorption line strategy;
each absorption line strategy comprises an adjustment rule I and an adjustment rule II; the target absorption lines corresponding to each absorption line strategy are different, and the target absorption lines under different regulation rules I correspond to different target voltage digital measuring value ranges;
When the ith absorption line strategy is executed, the laser modulation current is adjusted to be the modulation current I i And selectively starting the adjustment rule I and the adjustment rule II according to the input instruction until the output center wavelength of the semiconductor laser is adjusted to be within the center wavelength locking value interval W i The absorption line is adjusted to be the ith absorption line of the gas to be measured;
when the adjustment rule I is started, the microprocessor executes:
step A1, reading voltage value V of thermal sensitive resistor in laser RES And judging whether the condition is satisfied: digital voltage D DOWN Voltage value V less than or equal to RES Voltage digital quantity D less than or equal to up The method comprises the steps of carrying out a first treatment on the surface of the If not, turning to the step A2;
step A2, atThe voltage value V RES < the digital value D of the voltage DOWN At a preset interval a 1 Variable terminal voltage V of dynamic increase temperature controller p Then, the increased variable terminal voltage V is judged p Whether or not it is smaller than the maximum value V of the variable terminal voltage pMAX If yes, turning to the step A1; if not, the voltage V at the increased variable terminal p = V pMAX And fixed end voltage V of temperature controller N ＞V NMIN At a preset interval a 2 Dynamic reduction of fixed end voltage V of temperature controller N And converting the step A1;
at the voltage value V RES > the voltage digital quantity D up At a preset interval a 3 Variable terminal voltage V of dynamic reduction temperature controller p Then, the reduced variable terminal voltage V is judged p Whether or not it is greater than the minimum value V of the variable terminal voltage pMIN If yes, turning to the step A1; if not, then the voltage V at the reduced variable terminal p = V pMIN And fixed end voltage V of temperature controller N ＜V NMAX At a preset interval a 4 Dynamic increase of fixed end voltage V of temperature controller N And converting the step A1;
when the adjustment rule II is started, the microprocessor executes:
step B1, reading the voltage value V of the thermistor in the laser RES And judging whether the condition is satisfied: digital voltage D TDOWN Voltage value V less than or equal to RES Voltage digital quantity D less than or equal to Tup If not, turning to the step B2;
step B2, at the voltage value V RES < the digital value D of the voltage TDOWN At a preset interval a 5 Variable terminal voltage V of dynamic increase temperature controller p Then, the increased variable terminal voltage V is judged p Whether or not it is smaller than the maximum value V of the variable terminal voltage pMAX If yes, turning to the step B1; if not, the voltage V at the increased variable terminal p =V pMAX And fixed end voltage V of temperature controller N ＞V NMIN At a preset interval a 6 Dynamic reduction of fixed end voltage V of temperature controller N And converting to step B1;
at the voltage value V RES > the voltage digital quantity D Tup At a preset interval a 7 Variable terminal voltage V of dynamic reduction temperature controller p Then, the reduced variable terminal voltage V is judged p Whether or not it is greater than the minimum value V of the variable terminal voltage pMIN If yes, turning to the step B1; if not, then the voltage V at the reduced variable terminal p =V pMIN And fixed end voltage V of temperature controller N ＜V NMAX At a preset interval a 8 Dynamic increase of fixed end voltage V of temperature controller N And converting to step B1.
2. The method for detecting the concentration of laser infrared gas based on the dynamic absorption line according to claim 1, wherein after confirming that the execution of the adjustment rule i is completed, the microprocessor further detects whether the absorption line adjustment is successful:
extracting the second harmonic of the reference gas circuit signal to obtain the maximum value of the second harmonic of the reference gas circuit signal;
extracting a real-time voltage digital value measuring range according to a mapping relation between a pre-stored second harmonic maximum value and the voltage digital value measuring range;
judging whether a voltage digital measuring value range corresponding to an adjusting rule I in an ith absorption line strategy is matched with the real-time voltage digital measuring value range, if not, judging that the absorption line adjustment fails, and generating a first feedback message.
3. The method for detecting the concentration of the laser infrared gas based on the dynamic absorption line according to claim 1, wherein after confirming that the execution of the adjustment rule ii is completed, the microprocessor further detects whether the absorption line adjustment is successful:
reading the real-time center wavelength W 'of the output of a semiconductor laser' i Judging the real-time center wavelength W' i Center wavelength lock value interval W corresponding to adjustment rule ii in the ith absorption line policy i If the absorption line is matched, judging that the absorption line adjustment fails, and generating a second feedback message.
4. A laser infrared gas concentration detection system based on dynamic absorption lines is characterized in that: comprises a preprocessing unit, an absorption line strategy management unit and an absorption line strategy execution unit, wherein the absorption line strategy execution unit comprises an execution unit I, an execution unit II and an execution unit III,
the pretreatment unit is used for calibrating the concentration under the N item target absorption lines according to the type of the gas to be tested and the type of the laser before leaving the factory, and setting N-1 switching temperature thresholds corresponding to the N item target absorption lines;
the absorption line strategy management unit is used for reading a real-time environment temperature signal T outside the semiconductor laser when the laser infrared gas concentration is detected, and determining an absorption line adjustment strategy according to the real-time environment temperature signal T: if n=2, then the real-time ambient temperature signal T < the switching temperature threshold T 1 Executing the 1 st absorption line strategy; at the time that the real-time environment temperature signal T is more than or equal to the switching temperature threshold T 1 Executing the 2 nd absorption line strategy;
if n=3, then the real-time ambient temperature signal T < the switching temperature threshold T 1 Executing the 1 st absorption line strategy; at a switching temperature threshold T 1 The real-time environment temperature signal T is not less than the switching temperature threshold T 2 Executing the 2 nd absorption line strategy; at the real-time environment temperature signal T > the switching temperature threshold T 2 Executing a 3 rd absorption line strategy;
each absorption line strategy comprises an adjustment rule I and an adjustment rule II; the target absorption lines corresponding to each absorption line strategy are different, and the target absorption lines under different regulation rules I correspond to different target voltage digital measuring value ranges;
the execution unit I is used for adjusting the laser modulation current to be modulation current I when executing the ith absorption line strategy i And selectively starting the adjustment rule I and the adjustment rule II according to the input instruction until the output center wavelength of the semiconductor laser is adjusted to be within the center wavelength locking value interval W i The absorption line is adjusted to be the ith absorption line of the gas to be measured;
the execution unit ii is configured to execute, when the adjustment rule i is enabled:
step A1, reading voltage value V of thermal sensitive resistor in laser RES And judging whether the condition is satisfied: digital voltage D DOWN Voltage value V less than or equal to RES Voltage digital quantity D less than or equal to up The method comprises the steps of carrying out a first treatment on the surface of the If not, turning to the step A2;
step A2, at the voltage value V RES < the digital value D of the voltage DOWN At a preset interval a 1 Variable terminal voltage V of dynamic increase temperature controller p Then, the increased variable terminal voltage V is judged p Whether or not it is smaller than the maximum value V of the variable terminal voltage pMAX If yes, turning to the step A1; if not, the voltage V at the increased variable terminal p = V pMAX And fixed end voltage V of temperature controller N ＞V NMIN At a preset interval a 2 Dynamic reduction of fixed end voltage V of temperature controller N And converting the step A1;
at the voltage value V RES > the voltage digital quantity D up At a preset interval a 3 Variable terminal voltage V of dynamic reduction temperature controller p Then, the reduced variable terminal voltage V is judged p Whether or not it is greater than the minimum value V of the variable terminal voltage pMIN If yes, turning to the step A1; if not, then the voltage V at the reduced variable terminal p = V pMIN And fixed end voltage V of temperature controller N ＜V NMAX At a preset interval a 4 Dynamic increase of fixed end voltage V of temperature controller N And converting the step A1;
the execution unit III is configured to execute, when the adjustment rule II is enabled:
step B1, reading the voltage value V of the thermistor in the laser RES And judging whether the condition is satisfied: digital voltage D TDOWN Voltage value V less than or equal to RES Voltage digital quantity D less than or equal to Tup If not, turning to the step B2;
step B2, at the voltage value V RES < the digital value D of the voltage TDOWN At a preset interval a 5 Variable terminal voltage V of dynamic increase temperature controller p After that, judge to increasePost variable terminal voltage V p Whether or not it is smaller than the maximum value V of the variable terminal voltage pMAX If yes, turning to the step B1; if not, the voltage V at the increased variable terminal p =V pMAX And fixed end voltage V of temperature controller N ＞V NMIN At a preset interval a 6 Dynamic reduction of fixed end voltage V of temperature controller N And converting to step B1;
at the voltage value V RES > the voltage digital quantity D Tup At a preset interval a 7 Variable terminal voltage V of dynamic reduction temperature controller p Then, the reduced variable terminal voltage V is judged p Whether or not it is greater than the minimum value V of the variable terminal voltage pMIN If yes, turning to the step B1; if not, then the voltage V at the reduced variable terminal p =V pMIN And fixed end voltage V of temperature controller N ＜V NMAX At a preset interval a 8 Dynamic increase of fixed end voltage V of temperature controller N And converting to step B1.
5. The dynamic absorption line-based laser infrared gas concentration detection system according to claim 4, further comprising an absorption line adjustment confirmation unit i for:
after confirming that the execution of the adjustment rule I is finished, extracting the second harmonic of the reference gas path signal to obtain the maximum value of the second harmonic of the reference gas path signal;
Extracting a real-time voltage digital value measuring range according to a mapping relation between a pre-stored second harmonic maximum value and the voltage digital value measuring range;
judging whether a voltage digital measuring value range corresponding to an adjusting rule I in an ith absorption line strategy is matched with the real-time voltage digital measuring value range, if not, judging that the absorption line adjustment fails, and generating a first feedback message.
6. The dynamic absorption line-based laser infrared gas concentration detection system according to claim 4, further comprising an absorption line adjustment confirmation unit ii for:
upon confirmation of the adjustmentAfter rule II is executed, the real-time center wavelength W 'output by the semiconductor laser is read' i Judging the real-time center wavelength W' i Center wavelength lock value interval W corresponding to adjustment rule ii in the ith absorption line policy i If the absorption line is matched, judging that the absorption line adjustment fails, and generating a second feedback message.
7. Laser infrared gas concentration check out test set based on dynamic absorption line, its characterized in that: comprising a memory, a processor and a dynamic absorption line based laser infrared gas concentration detection program stored on the memory and operable on the processor, which, when executed by the processor, implements the steps of the dynamic absorption line based laser infrared gas concentration detection method as claimed in any one of claims 1-3.
8. A readable storage medium having instructions stored thereon, characterized by: the instructions, when executed by a processor, implement the steps of a dynamic absorption line based laser infrared gas concentration detection method as recited in any one of claims 1-3.
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