CN201697876U - Gas in-place measuring device - Google Patents

Gas in-place measuring device Download PDF

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CN201697876U
CN201697876U CN2010202540942U CN201020254094U CN201697876U CN 201697876 U CN201697876 U CN 201697876U CN 2010202540942 U CN2010202540942 U CN 2010202540942U CN 201020254094 U CN201020254094 U CN 201020254094U CN 201697876 U CN201697876 U CN 201697876U
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gas
measured
absorption
light
unit
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黄伟
顾海涛
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Focused Photonics Hangzhou Inc
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Focused Photonics Hangzhou Inc
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Abstract

The utility model relates to a gas in-place measuring device, which is characterized by comprising a laser, a detector, an analyzing unit, a blowing unit and a calibrating unit. Frequency of output light of the laser corresponds to absorption spectral lines of a gas to be measured, including an absorption spectral line I and an absorption spectral line II, in case of unit concentration and unit optical path, absorption of the gas to be measured in the measured gas is no lower than that of the gas to be measured in the blowing gas by five times at the absorption spectral line I due to temperature difference between the measured gas and the blowing gas, the detector is used for receiving measuring light which passes through the blowing gas and the measured gas and corresponds to the absorption spectral line I, or calibrating light which passes through standard gas of the gas to be measured and corresponds to the absorption spectral line II, the analyzing unit is used for obtaining content of the gas to be measured in the measured gas according to the signals of the detector, the blowing unit is used for providing gas to blow measuring light path outside an area of the gas to be measured, the blowing gas contains the gas to be measured, and the calibrating unit comprises the standard gas of the gas to be measured. The gas in-place measuring device has the advantages of high precision, low cost and the like.

Description

The on-position measure device of gas
Technical field
The utility model relates to gasmetry, particularly utilizes the device of gas absorption spectra technology on-position measure high-temperature gas.
Background technology
In fields such as waste incineration,, need monitor the O in the combustion furnace accurately and timely in order to control the burning efficiency in the combustion furnace 2Content.O in the combustion furnace 2The measurement of concetration scope is 0～25%, and temperature range is 800～900 ℃.
At present, the laser absorption spectrum gas analysis device based on DLAS (Diode Laser Absorption Spectroscopy) technology is widely used in the gasmetry.The ultimate principle of DLAS technology is: tuning measurement light wavelength makes it correspond to the absorption line of gas to be measured; Measuring light is passed gas to be measured and is detected the device reception and is converted to electric signal, obtains the absorption of measuring light at described absorption line place, obtains the parameters such as concentration of gas to be measured according to Beer-Lambert law.The DLAS technology has plurality of advantages, as: the original position on-line measurement, the response time is very short, can reach Millisecond, can realize continuous coverage; Measurement lower limit is low, can be used for measuring the gas that concentration is the ppb level; The measuring accuracy height.
As shown in Figure 1, a kind of formula oxygen measurement device on the throne, Optical Transmit Unit 14 and light receiving unit 15 are arranged on the both sides of combustion furnace 10, isolate gas 11 to be measured by diaphragm 16,17 simultaneously; Wherein, light source 2 is arranged in the Optical Transmit Unit 14, and detector 20 is arranged in the light receiving unit 15.The measuring beam 19 that light source 2 sends by the transmitance of analytic unit 30 analysis to measure light beams 19, thereby is obtained parameter such as oxygen concentration in the gas 11 to be measured by the oxygen absorption in the gas 11 to be measured.
Outside air contains oxygen, and oxygen can enter in described Optical Transmit Unit 14 and the light receiving unit 15, has absorbed part measuring beam 19, thereby has influenced measuring accuracy.
In addition, the particle in gas 11 to be measured more for a long time, particle can stick on the described diaphragm 16,17, greatly reduces the transmitance of measuring beam 19, even can to make transmittance be zero, has had a strong impact on measuring accuracy, even measurement can't be carried out.
In order to get rid of above-mentioned adverse effect, this measurement mechanism has also disposed purging unit 21, charges into purge gas 22 in described Optical Transmit Unit 14 and light receiving unit 15.Perhaps the side to described diaphragm 16,17 contiguous gases 11 to be measured charges into purge gas 22, thereby makes the particle in the gas 11 to be measured can't pollute described diaphragm 16,17, and above-mentioned measure has improved measuring accuracy greatly, has also improved the sustainability of measuring.
Usually use high pure nitrogen as purge gas 22, but in fields such as waste incineration, high pure nitrogen is difficult to obtain, and has, also contains oxygen in the high pure nitrogen again, measures the oxygen meeting absorptiometry light in the purge gas on the light path, thereby reduced measuring accuracy.
In order to solve the problems of the technologies described above, usually way is: oxygen sensor is set in Optical Transmit Unit, record concentration of oxygen in the purge gas, by the deduction purge gas (comprise in the Optical Transmit Unit or light receiving unit in or diaphragm close on the purge gas of gas one side to be measured) in oxygen to the absorption of measuring light, and then obtain in the combustion furnace parameter such as oxygen concentration.The weak point of this method is mainly:
1, the measuring accuracy of described gas sensor is low, and is subjected to gaseous tension, Temperature Influence bigger.
2, be limited by measuring principle, the response time of gas sensor is long, can not measure in real time.
3, poor stability, the performance of described gas sensor descends comparatively fast with the increase of service time.
4, gas sensor life-span weak point, constantly the sensor of changing has also improved the measurement cost.
The utility model content
In order to solve above-mentioned deficiency of the prior art, the utility model provides a kind of on-position measure device of simple in structure, measuring accuracy is high, cost is low gas.
To achieve these goals, the utility model adopts following technical scheme respectively:
The measurement mechanism of oxygen in a kind of combustion furnace, characteristics are: described device comprises:
Laser instrument, the absorption line of the corresponding gas to be measured of output light frequency: absorption line I, absorption line II; Under unit concentration unit light path, at absorption line I place, the temperature difference of tested gas and purge gas causes that the absorption of gas to be measured in the tested gas is not less than 5 times of absorption of gas to be measured in the purge gas;
Detector is used to receive the measuring light corresponding to absorption line I of passing behind purge gas, the tested gas, or passes the nominal light corresponding to absorption line II behind the gas gas to be measured;
Analytic unit is used for obtaining according to the signal of detector the content of gas to be measured in the tested gas;
Purge the unit, be used to provide gas to go to purge the outer measurement light path of tested gas zones, contain gas to be measured in the purge gas;
Demarcate the unit, comprise the gas of gas to be measured.
Further, described demarcation unit comprises calibrating tube.
Further, be provided with on the described calibrating tube and be convenient to the coupling arrangement that connects with laser instrument, detector.
Further, laser instrument is connected with calibrating tube by optical fiber, in measuring light path and/or demarcation light path control device is set, and is used for whether passing through of control survey light or nominal light.
As preferably, described gas to be measured is oxygen, and described absorption line I is following arbitrary frequency: 13164.18cm -1, 13164.93cm -1, 13161.93cm -1, 13159.44cm -1, 13154.66cm -1, 13009.89cm -1, 13001.35cm -1, 13000.82cm -1, 12988.48cm -1, 12979.66cm -1, 12976.54cm -1, 12966.42cm -1
As preferably, described gas to be measured is oxygen, and described absorption line II is following arbitrary frequency: 13163.78cm -1, 13164.69cm -1, 13161.62cm -1, 13158.74cm -1, 13154.19cm -1, 13010.82cm -1, 13001.72cm -1, 12999.97cm -1, 12988.73cm -1, 12978.83cm -1, 12977.12cm -1, 12966.82cm -1
As preferably, described purging unit provides air as purge gas.
Compared with prior art, the utility model has following beneficial effect:
1, measuring accuracy height
The utility model has selected to absorb under the normal temperature absorption line I very weak, that high temperature absorbs stronger gas to be measured down: the temperature of purge gas is normal temperature substantially in Optical Transmit Unit, light receiving unit and the measurement passage, the temperature of combustion furnace then surpasses 1000K, a little less than gas to be measured is compared to the absorption of measuring light to high-temperature gas in the absorption of measuring light and the pipeline in the purging air; And the light path of measuring light in purge gas is less than the light path in pipeline; Have, the concentration change of each gas is very little in the air again, therefore, the variation of the concentration of gas to be measured, temperature, pressure in the purge gas and cause very little to measuring light in the variation of the absorption at spectral line I place, can ignore.
In order further to improve the precision of measuring, also need the calibration measurements device, in the output light frequency scope of laser instrument, selected an other absorption line II of gas to be measured, make that gas to be measured at normal temperatures is stronger to the absorption of nominal light at absorption line II place.
2, cost is low
The utility model can directly use air as purge gas, has lowered the cost of purge gas significantly.
Can ignore to the variation of the absorption of measuring light owing to the variation of gas to be measured in the purge gas causes, therefore need not to be provided with the content that special gas sensor to be measured removes to measure gas to be measured in the purge gas.
Description of drawings
Fig. 1 is the structural representation of oxygen measurement device in the prior art;
Fig. 2 is the structural representation of oxygen measurement device among the utility model embodiment 1;
Fig. 3 is the structural representation of oxygen measurement device among the utility model embodiment 2;
Fig. 4 is the absorption line synoptic diagram of selecting among the embodiment 1;
Fig. 5 is the absorption line synoptic diagram of selecting among the embodiment 2.
Embodiment
Below in conjunction with drawings and Examples, the utility model is described in further details.
Embodiment 1:
As shown in Figure 2, the on-position measure device of oxygen in a kind of incinerator, the temperature in the incinerator is about 1223K, described measurement mechanism comprises:
Optical Transmit Unit 14 comprises laser instrument 25 and driver module, and the output light frequency of described laser instrument 25 comprises the frequency v corresponding to the absorption line I of oxygen 1=13164.18cm -1, corresponding to the frequency v of the absorption line II of oxygen 2=13163.78cm -1Under driver module work, the output light frequency of laser instrument 25 can inswept said frequencies.As shown in Figure 4, under unit concentration unit light path, at the absorption line I place of oxygen, the absorption under the high temperature (1223K) substantially exceeds the absorption under the normal temperature (300K), above 15 times.
Light receiving unit 15 comprises detector 20, and the selection of detector 20 is state of the art, does not repeat them here.
Analytic unit 30, the signal that is used for sending here according to detector 20, purge oxygen in the light path to the absorption of measuring light and in the analytic combustion stove 10 high-temperature gases in the absorption of absorption line I place measuring light, thereby draw the content of combustion furnace 10 interior oxygen.
Above-mentioned Optical Transmit Unit 14, light receiving unit 15 connect on combustion furnace 10 by devices such as flange, valves, and the measuring light 19 that makes Optical Transmit Unit 14 send can be received by light receiving unit 15.Separate test environment and Optical Transmit Unit 14 by diaphragm 16, separate test environment and light receiving unit 15 by diaphragm 17.
Purge unit 21, be used for providing air 23 (content of air oxygen is very stable) to remove to purge the inside and the measurement passage of Optical Transmit Unit 14, light receiving unit 15.The light path of measuring light 19 in combustion furnace is 4m, and the light path in purge gas is 1.2m.
Demarcate the unit, comprise calibrating tube 9 and demarcate the source of the gas (not shown), the two ends of calibrating tube 9 are provided with is convenient to the coupling arrangement that connects with Optical Transmit Unit 14, light receiving unit 15, demarcates zero gas and gas that source of the gas comprises oxygen.
Present embodiment has also disclosed a kind of on-position measure method of oxygen, is used to measure concentration of oxygen in the incinerator, and the temperature in the incinerator is about 1223K, and the content of oxygen is about 10%, and described measuring method is specially:
As shown in Figure 4, select the frequency v of the absorption line I of oxygen 1=13164.18cm -1, absorption line II frequency v 2=13163.78cm -1Under unit concentration unit light path, at the absorption line I place of oxygen, the absorption under the high temperature (1223K) substantially exceeds the absorption under the normal temperature (300K), above 15 times; Determine laser instrument 25 according to the absorption line of selecting, make under the effect of Laser Drive module that the output light frequency of laser instrument 25 can inswept above-mentioned absorption line;
Under the measurement state:
The air 23 that purging unit 21 provides purges Optical Transmit Unit 14, light receiving unit 15 and measures passage, is normal temperature in Optical Transmit Unit 14, light receiving unit 15 and the measurement passage;
Under the driver module effect, the output light frequency of laser instrument 25 is tuned to v 1=13164.18cm -1Measuring light 19 is detected device 20 receptions after passing the high-temperature gas of measuring in passage, the combustion furnace 10, and is converted to electric signal, the signal that analytic unit 30 is sent here according to detector 20, deduction falls to purge the absorption of the interior oxygen of light path to measuring light again, thereby obtains high-temperature gas to frequency v 1=13164.18cm -1The absorption of place output light, analyze and obtain combustion furnace 10 interior concentration of oxygen X after this absorptions:
Wherein, K is the calibration coefficient of measurement mechanism, b 0Be the zero point of measurement mechanism, P, T, L are respectively pressure, temperature, the light path of tested gas, and (P is temperature, the pressure correlation function of tested gas at spectral line I place T) to f, and V is the detected absorption signal of detector, V InhaleBe the absorption signal that obtains after the purge gas absorbing light.
V Blow=KX BlowL BlowF (P Blow, T Blow)
Wherein, X BlowBeing purge gas concentration, is 20.95%, and K is a calibration coefficient, P BlowPressure for purge gas is about 1atm, T BlowBe the purge gas temperature, variation range is-20～50 ℃, L BlowFor purging light path, f (P Blow, T Blow) be temperature, the pressure correlation function of purge gas at spectral line I place.
As shown in Figure 4, at normal temperatures, the oxygen in Optical Transmit Unit 14, light receiving unit 15 and the measurement passage in the purging air is to v 1=13164.18cm -1A little less than the absorption very of frequencies of light; Temperature in the combustion furnace is about 1223K, and oxygen is v to frequency in the stove 1=13164.18cm -1The absorption of output light stronger, surpass 15 times that normal temperature absorbs down; Have, the light path (1.2m) of measuring light 19 in purge gas is less than the light path in combustion furnace (4m) again; Also have, concentration of oxygen is more stable in the purging air.Therefore, the temperature of purging air, pressure change the oxygen that causes at v 1=13164.18cm -1The place is to the absorption V of measuring light 19 BlowVariation very little,, can ignore less than 1% to measured oxygen concentration result's influence.
Elongated along with service time needs to demarcate entire measuring device, is specially:
Optical Transmit Unit 14 and light-receiving list are 15 yuan under the dismounting, and Optical Transmit Unit 14 and light receiving unit 15 are installed on the calibrating tube 9, the zero gas and the demarcation of aerating oxygens respectively in the calibrating tube 9;
Under the effect of driver module, the output light frequency of laser instrument 1 is tuned to v 2=13163.78cm -1, output light passes the gas in the calibrating tube 9, is detected device 20 afterwards and receives and be converted to electric signal, goes to demarcate according to the result of analytic unit 30, thereby obtains calibration coefficient K:
K = V - b 0 X · L · f ( P , T )
Wherein, X is a gas concentration, b 0Be the zero point of measurement mechanism, P, T, L are respectively timing signal gaseous tension, temperature, light path, and (P is at spectral line v T) to f 2=13163.78cm -1Temperature, the pressure correlation function at place, V is that detector detects absorption signal.
After demarcate finishing, Optical Transmit Unit 14 and light receiving unit 15 are reinstalled to the both sides of combustion furnace 10, and with the output light frequency of laser instrument 25 be tuned to v 1=13164.18cm -1, the content of oxygen in the combustion furnace 10 is measured in continuation.
Therefore, because the appropriate selection of oxygen absorption spectral line makes it possible to utilize air as purge gas, and need not to measure constantly the oxygen content in the purging air, reduced the measurement cost.
Embodiment 2:
As shown in Figure 3, the on-position measure device of oxygen in a kind of incinerator, the temperature in the incinerator is about 1223K, described measurement mechanism comprises:
Optical Transmit Unit 8 comprises laser instrument 27 and driver module, optical branching device 5, and the output light frequency of described laser instrument 27 comprises the frequency v corresponding to the absorption line I of oxygen 1=13164.93cm -1, corresponding to the frequency v of the absorption line II of oxygen 2=13164.69cm -1Under driver module work, the output light frequency of laser instrument 27 can inswept said frequencies.As shown in Figure 5, under unit concentration unit light path, at the absorption line I place of oxygen, the absorption under the high temperature (1223K) substantially exceeds the absorption under the normal temperature (300K), has surpassed 8 times.
Light receiving unit 6 comprises detector 28, and the selection of detector 28 is state of the art, does not repeat them here.
Analytic unit 30, purges gas to be measured in the light path to the absorption to absorption line I place measuring light of the absorption analysis high-temperature gas of measuring light at the signal that is used for sending here according to detector 28, thereby draws the content of combustion furnace 10 interior oxygen.
Above-mentioned Optical Transmit Unit 8, light receiving unit 6 connect on combustion furnace 10 by devices such as flange, valves, and the measuring light that makes laser instrument 27 send can be detected device 28 and receive.Separate test environment and Optical Transmit Unit 8 by diaphragm 16, separate test environment and light receiving unit 6 by diaphragm 17.
Purge unit 21, be used to provide air 23 to remove to purge the inside and the measurement passage of Optical Transmit Unit 8, light receiving unit 6.
Demarcate the unit, comprise calibrating tube 9 and demarcate the source of the gas (not shown), the two ends of calibrating tube 9 connect shunt 5 and detector 28 by optical fiber, demarcate zero gas and gas that source of the gas comprises oxygen.
By the switching of optical branching device 5, measurement mechanism is in measures or the demarcation state.When needing to measure, by switching, the light that laser instrument 27 sends becomes measuring light 19, and measuring light 19 is detected device 28 receptions after passing and measuring passage, combustion furnace 10, and do not have light to pass through calibrating tube 9 this moment.Need timing signal, by switching, the light that laser instrument 27 sends becomes nominal light 26, and nominal light 26 is detected device 28 receptions after passing calibrating tube 9, and do not have light to pass through combustion furnace 10 this moment.
The light path of described measuring light 19 in combustion furnace 10 is 4m, and the light path in purge gas is 1.2m.
Present embodiment has also disclosed a kind of on-position measure method of oxygen, is used to measure concentration of oxygen in the incinerator, and the temperature in the incinerator is about 1223K, and the content of oxygen is about 10%, and described measuring method is specially:
As shown in Figure 5, select the frequency v of the absorption line I of oxygen 1=13164.93cm -1, absorption line II frequency v 2=13164.69cm -1Under unit concentration unit light path, at the absorption line I place of oxygen, the absorption under the high temperature (1223K) substantially exceeds the absorption under the normal temperature (300K), above 8 times.Determine laser instrument 27 according to the absorption line of selecting, make under the effect of Laser Drive module that the output light frequency of laser instrument 27 can inswept above-mentioned absorption line; Determine laser instrument 27 according to the absorption line of selecting, make that under the effect of Laser Drive module the output light frequency of laser instrument 27 can inswept above-mentioned absorption line.
Under the measurement state:
The air 23 that purging unit 21 provides purges Optical Transmit Unit 8, light receiving unit 6 and measures passage, is normal temperature in Optical Transmit Unit, light receiving unit and the measurement passage;
Under the driver module effect, the output light frequency of laser instrument 27 is tuned to v 1=13164.93cm -1, by the switching of optical branching device 5, output light is measuring light 19, measuring light 19 is detected device 28 receptions after passing the high-temperature gas of measuring in passage, the combustion furnace 10, and is converted to electric signal; The signal that analytic unit 30 is sent here according to detector 20, deduction falls to purge the absorption of the interior oxygen of light path to measuring light again, thereby obtains high-temperature gas to frequency v 1=13164.93cm -1The absorption of place output light, analyze and obtain combustion furnace 10 interior concentration of oxygen X after this absorptions:
Figure BSA00000182361400091
Wherein, K is the calibration coefficient of measurement mechanism, b 0Be the zero point of measurement mechanism, P, T, L are respectively pressure, temperature, the light path of tested gas, and (P is temperature, the pressure correlation function of tested gas at spectral line I place T) to f, and V is the detected absorption signal of detector, V InhaleBe the absorption signal that obtains after the purge gas absorbing light.
V Blow=KX BlowL BlowF (P Blow, T Blow)
Wherein, X BlowBeing purge gas concentration, is 20.95%, and K is a calibration coefficient, P BlowPressure for purge gas is about 1atm, T BlowBe the purge gas temperature, variation range is-20～50 ℃, L BlowFor purging light path, f (P Blow, T Blow) be temperature, the pressure correlation function of purge gas at spectral line I place.
As shown in Figure 5, at normal temperatures, the oxygen in Optical Transmit Unit 8, light receiving unit 6 and the measurement passage in the purging air is to v 1=13164.93cm -1A little less than the absorption very of frequencies of light; Temperature in the combustion furnace is about 1223K, and oxygen is v to frequency in the stove 1=13164.93cm -1The absorption of output light stronger: under unit concentration unit light path, at the absorption line I place of oxygen, the absorption under the high temperature (1223K) surpasses the absorption under the normal temperature (300K), above 8 times; Also have, the light path (1.2m) of measuring light 19 in purge gas is less than the light path in combustion furnace 10 (4m); Have, concentration of oxygen is very stable in the purging air again, therefore, oxygen concentration in the purging air, temperature, pressure change cause at v 1=13164.93cm -1The place is very little to the variation of the absorption of measuring light 19,, can ignore less than 1% to measurement of concetration result's influence;
Elongated along with service time needs to demarcate entire measuring device, is specially:
Under the effect of driver module, the output light frequency of laser instrument 27 is tuned to v 2=13164.69cm -1, by the switching of optical branching device 5, output light becomes nominal light 26, and nominal light 26 is passed the gas in the calibrating tube 9, is detected device 28 afterwards and receives and be converted to electric signal, goes to demarcate according to the analysis result of analytic unit 30, thereby obtains calibration coefficient K:
K = V - b 0 X · L · f ( P , T )
Wherein, X is a gas concentration, b 0Be the zero point of measurement mechanism, P, T, L are respectively timing signal gaseous tension, temperature, light path, and (P is at spectral line v T) to f 2=13163.78cm -1Temperature, pressure correlation function, V is that detector detects absorption signal.
After demarcate finishing, with the output light frequency of laser instrument 27 be tuned to v 2=13164.93cm -1, pass through the switching of optical branching device 5 again, thereby continue to measure the content of oxygen in the combustion furnace 10.
Therefore, because the appropriate selection of oxygen absorption spectral line makes it possible to utilize air as purge gas, and need not to measure constantly the oxygen content in the purging air, reduced the measurement cost.
Embodiment 3:
The on-position measure device of oxygen in a kind of incinerator, as different from Example 2:
1, optical branching device no longer is set, but in measurement light path (light path that measuring light forms), first photoswitch is set between laser instrument and detector, in demarcation light path (light path that nominal light forms), second photoswitch is set between laser instrument and detector.
When being in the measurement state, first photoswitch is opened, and second photoswitch is closed; When being in the demarcation state, first photoswitch is closed, and second photoswitch is opened.
2, measuring light total light path in purge gas is 0.3m, and the content of oxygen is 21% in the purging air; Measuring light path in the combustion furnace is 3m, and the content of oxygen is about 10%; Under unit concentration unit light path, at the absorption line I place of oxygen, the absorption under the high temperature (1223K) substantially exceeds the absorption under the normal temperature (300K), above 15 times.As seen, oxygen is to 1% of the absorption of measuring light in the combustion furnace to the absorption of measuring light for oxygen in the purge gas, and purge gas can be ignored to the absorption of measuring light.
The on-position measure method of oxygen in a kind of incinerator, as different from Example 2:
1, optical branching device no longer is set, but in measurement light path (light path that measuring light forms), first photoswitch is set between laser instrument and detector, in demarcation light path (light path that nominal light forms), second photoswitch is set between laser instrument and detector.
When being in the measurement state, first photoswitch is opened, and second photoswitch is closed; When being in the demarcation state, first photoswitch is closed, and second photoswitch is opened.
2, the computing formula of oxygen concentration X is in the tested gas:
Figure BSA00000182361400111
Wherein, K is the calibration coefficient of measurement mechanism, b 0Be the zero point of measurement mechanism, P, T, L are respectively pressure, temperature, the light path of tested gas, and (P is temperature, the pressure correlation function of tested gas at absorption line I place T) to f, and V is the detected absorption signal of detector, V BlowBe the absorption signal that obtains after the purge gas absorbing light.
In the present embodiment, measuring light total light path in purge gas is 0.3m, and the content of oxygen is 21% in the purging air, and measuring light path in the combustion furnace is 3m, and the content of oxygen is about 10%; Under unit concentration unit light path, at the absorption line I place of oxygen, the absorption under the high temperature (1223K) substantially exceeds the absorption under the normal temperature (300K), above 15 times.As seen, in the purge gas oxygen to the absorption of measuring light less than oxygen in the combustion furnace to 1% of the absorption of measuring light, purge gas can be ignored to the absorption of measuring light, the computing formula of concentration of oxygen X is reduced to:
X = V - b 0 K · L · f ( P , T )
Above-mentioned embodiment should not be construed as the restriction to the utility model protection domain.Having enumerated the measurement of oxygen among the embodiment, can also be other gas certainly, as carbon dioxide etc.Under the situation that does not break away from the utility model spirit, any type of change that the utility model is made all should fall within the protection domain of the present utility model.

Claims (6)

1. the on-position measure device of gas, it is characterized in that: described device comprises:
Laser instrument, the absorption line of the corresponding gas to be measured of output light frequency: absorption line I, absorption line II; Under unit concentration unit light path, at absorption line I place, the temperature difference of tested gas and purge gas causes that the absorption of gas to be measured in the tested gas is not less than 5 times of absorption of gas to be measured in the purge gas;
Detector is used to receive the measuring light corresponding to absorption line I of passing behind purge gas, the tested gas, or passes the nominal light corresponding to absorption line II behind the gas gas to be measured;
Analytic unit is used for obtaining according to the signal of detector the content of gas to be measured in the tested gas;
Purge the unit, be used to provide gas to go to purge the outer measurement light path of tested gas zones, contain gas to be measured in the purge gas;
Demarcate the unit, comprise the gas of gas to be measured.
2. measurement mechanism according to claim 1 is characterized in that: described demarcation unit comprises calibrating tube.
3. measurement mechanism according to claim 2 is characterized in that: be provided with on the described calibrating tube and be convenient to the coupling arrangement that connects with laser instrument, detector.
4. measurement mechanism according to claim 2 is characterized in that: laser instrument is connected with calibrating tube by optical fiber, in measuring light path and/or demarcation light path control device is set, and is used for whether passing through of control survey light or nominal light.
5. measurement mechanism according to claim 1 is characterized in that: described gas to be measured is oxygen, and described absorption line I is following arbitrary frequency: 13164.18cm -1, 13164.93cm -1, 13161.93cm -1, 13159.44cm -1, 13154.66cm -1, 13009.89cm -1, 13001.35cm -1, 13000.82cm -1, 12988.48cm -1, 12979.66cm -1, 12976.54cm -1, 12966.42cm -1
6. measurement mechanism according to claim 1 is characterized in that: described gas to be measured is oxygen, and described absorption line II is following arbitrary frequency: 13163.78cm -1, 13164.69cm -1, 13161.62cm -1, 13158.74cm -1, 13154.19cm -1, 13010.82cm -1, 13001.72cm -1, 12999.97cm -1, 12988.73cm -1, 12978.83cm -1, 12977.12cm -1, 12966.82cm -1
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108780039A (en) * 2016-03-24 2018-11-09 洋马株式会社 Gas concentration measuring apparatus

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108780039A (en) * 2016-03-24 2018-11-09 洋马株式会社 Gas concentration measuring apparatus

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