MT 137.1-1986 Method for determination of harmful gas carbon monoxide in mine air
Some standard content:
Standard of the Ministry of Coal Industry of the People's Republic of China Harmful Gases in Mine Air
Determination Method of Carbon Monoxide
This standard applies to the determination of carbon monoxide concentration in air (or gas) underground in coal mines. 1 General Provisions
1.1 Carbon monoxide concentration is expressed in ppm (volume/volume). 1 ppm = 0.0001%.
1.2 Calibration Gas
MT 137.1-86
1.2.1 Prepared by static gas distribution method. The preparation method is in accordance with Appendix A of MT67-82 "Comparative Long Carbon Monoxide Calibration Tube". 1.2.2 Order carbon monoxide standard gas samples according to the measurement range. 1.3 When there is a dispute over the measurement results, use carbon monoxide standard gas samples for arbitration. 1.4 When using a bladder to collect gas samples, it shall not exceed 12 hours from sampling to completion of the measurement. Sampling plate 3000~6000 ml. 1.5 When the carbon monoxide concentration exceeds the relevant provisions of the "Coal Mine Safety Regulations" or the carbon monoxide cannot be measured by the calibration tube method, a gas sample must be taken to the ground laboratory for determination using the method specified in Article 2.2 or Article 2.3 of this standard. 1.6 When using the mercury replacement method (mercuric oxide-selenium test paper method), when the selenium test paper has been placed for a long time or the instrument used is different from the type of instrument used to calibrate the selenium test paper, the selenium test paper must be re-calibrated with calibration gas before use. 1.7 When using gas chromatography, in order to ensure the accuracy of the measurement results, repeated sampling is not allowed (that is, the next gas sample cannot be injected before the chromatographic peak of the previous gas sample has been completely discharged). When using a calibration curve for quantification, the accuracy of the calibration curve should be frequently verified with calibration gas. 2 Determination method
2.1 Length-ratio test tube method
2.1.1 Principle of the method: When the gas sample passes through a glass tube filled with an indicator gel adsorbing diiodine pentoxide, carbon monoxide reacts with diiodine pentoxide to generate a brown (or green-brown) color change layer of free iodine. The height of the color change layer indicates the concentration of carbon monoxide. 2.1.2 Apparatus
2.1.2.1 Test tube. The test tube should comply with the relevant provisions of MT 67-82. According to the range of carbon monoxide concentration, the test tube is generally divided into three types (see Table 1).
Table 1 Model of calibration tube
Measurement range
5~～100
10～500
100～5000
The calibration tube is used under the condition of ambient temperature of 15～35℃, atmospheric pressure of 700~～800 mmHg, and the interference gas contained can be removed. Ministry of Coal Industry of the People's Republic of China Issued on March 5, 1986 Implemented on April 1, 1986
MT 137.1--86
Before using the calibration tube, its quality shall be spot-checked with calibration gas. If it is found that it does not meet the relevant provisions of MT67-82, it shall not be used. 2.1.2.2 Calibrator: There are four types of calibrators used in conjunction with the calibration tube (see Figure 1), which can be selected according to the specific situation. The relative deviation of the calibrator volume shall not exceed ±5% of the nominal volume. 8
2.1.8Preparation before determination
Figure 1 Schematic diagram of the tester
2.1.3.1Check the air tightness of the tester: According to the method specified in the instruction manual, insert the unopened test tube into the exhaust (or air intake) port of the tester to check the air tightness of the tester. If leakage is found, it shall not be used. 2.1.3.2Appearance inspection of the test tube: When using, check whether the tip of the test tube is broken, whether the reagent is loose, mixed, or discolored, whether the scale is clear, and whether the zero mark coincides with the interface between the indicator glue and the isolation layer. 2.1.4Determination steps: The determination steps shall be carried out strictly in accordance with the instruction manual, and two test tubes shall be used for each determination. 2.1.5Processing of measurement results
2.1.5.1When the allowable difference of the measurement values of the two test tubes meets the requirements of Table 2 of this standard, take their arithmetic mean as the measurement result. If it does not meet the requirements of Table 2, a third test shall be conducted, and the arithmetic mean of the two test values within the tolerance shall be taken. Table 2 Permissible difference of test tube measurement values
Test tube model
2.1.5.2 Selection of average value
Measured concentration
50~250
Type 1 test tube calculates to one decimal place, and reports the integer after rounding off according to the digital rounding rules. Type 2 test tube calculates to the unit digit, and reports the tens digit after rounding off according to the digital rounding rules. Type 3 test tube calculates to the tens digit, and reports the hundreds digit after rounding off according to the digital rounding rules. 586
2.2 Mercury replacement method (mercury oxide-selenium test paper method) mT 137.1-86
2.2.1 Principle of the method: At a certain temperature, carbon monoxide reacts with mercury oxide to generate mercury vapor, which then reacts with selenium on the selenium test paper to generate a black mark of mercury selenide. The length of the black mark is measured to calculate the carbon monoxide concentration in the gas sample. The determination range of this method is 0-100ppm, and the sensitivity is 2 ppm.
2.2.2 Instrumentation
2.2.2.1 Fixed determination device (Figure 2).
Figure 2 Fixed measuring device
1 Gas sample measuring tube, 2 - a level bottle, 3 capillary flowmeter, 4, 5 - gas drying tube; 6 - an activated carbon tube, 7 - a U-shaped reaction tube 8, 9 mercury thermometers, 10, 11 - a tubular heating furnace, 12 - an insulated box Gas sample measuring tube 1 is an eight-ball measuring tube with a water jacket, each ball has a volume of 50±1 ml, the upper end of the measuring tube has a four-way piston A with a 90° passage, the lower end of the measuring tube has a three-way pipe, the upward branch of the tube has a two-way piston B, the upper part is connected to the measuring tube, and the right branch has a two-way piston, which is connected to the water source to transport the gas sample.
The volume of the level bottle 2 is 450-500 ml.
Gas drying tube 4 is filled with anhydrous calcium fluoride.
Gas drying tube 5 is filled with magnesium perchlorate.
Activated carbon tube 6 contains granular activated carbon. The dimensions of the U-shaped reaction tube are shown in Figure 2. Mercuric oxide is placed in the left tube and selenium test paper is placed in the right tube. The range of mercury thermometers 8 and 9 is 0~360℃. The inner diameter of the tubular heating furnaces 10 and 11 is 30 mm and the height is 130 mm. The center distance between the two furnaces is 60 mm. The furnaces are wrapped with a layer of mica paper and electric heating wires are wound outside. Each of the two furnaces has a transformer to control the furnace temperature. The insulation box 12 has a volume of 250×180×180 mm and contains asbestos ash (or ceramic wool) insulation material. 2.2.2.2 Portable measurement device (Figure 3). 587
MT 137.1-86
Figure 3 Portable measuring device
1 Power switch, 2- Terminal, 3- Fuse, 4- Temperature regulator, 5- Float flowmeter; 6- Air inlet, 7- Needle flow adjustment width: 8- U-shaped reaction tube: 9- Metal three-way valve The adjustment range of temperature regulator 4 is 0-300℃, and the accuracy is 2.5 level. The range of float flowmeter 5 is 0-50 ml/min 0-500 ml/min.
2.2.3 Reagents and materials
2.2.8.1 Reagents
a. Calcium chloride anhydrous: chemically pure, granular, magnesium pernitrate, chemically pure, granular,
Activated carbon: industrial use, granular,
Mercury oxide: chemically pure, granular, orange-red in color, rich in pores, without metallic mercury luster, d.
Color-changing silica gel: industrial use, granular.
2.2.3.2 Materials
Selenium test paper: Selenium test paper is divided into two types: activation and measurement. The paper strip is 140 mm long and 3 mm wide. a.
b. Latex tube: inner diameter 5 to 7 mm.
2.2.4 Air tightness check: After the measuring device is assembled, block the gas outlet of the system. If the flow meter returns to zero, it means that the air tightness is good. Otherwise, it should be checked in sections for processing.
2.2.5 Determination operation
2.2.5.1 Operation of fixed determination device
a. Activation of mercuric oxide and blank determination: Heat up the incubator in Figure 2, insert a concentrated selenium test paper for activation into the paper tube, the insertion depth is 180 mm from the tube end, and then start to let in clean air, which enters the U-shaped reaction tube through tubes c and d, and the air flow rate is controlled to be about 250 ml/min. Use a transformer to maintain the temperature of the mercuric oxide tube at 250±1℃ and the temperature of the test paper tube at 140±2℃. Continue to let in clean air, and when the black mark on the selenium test paper strip reaches the top, replace it with a new paper strip. When the black mark is generated very slowly, it is a sign that the activation is about to be completed. Then cool the mercuric oxide tube furnace and maintain the temperature of the mercuric oxide tube at 180±1℃. At this time, change the flow rate of the net air to 10±0.5 ml/min, take out the concentrated selenium test strip for activation, and insert the selenium test strip for determination (the insertion depth is 180 mm from the tube end), and continue ventilation for 5 minutes.After three consecutive measurements, there is no black mark on the paper strip, indicating that the activation has been completed. Newly installed mercuric oxide can generally be activated in 4 to 6 hours. After that, it should be activated for 1 hour according to the above method before the start of each day's measurement. After checking that the blank is qualified, the measurement can be carried out. When not being measured, mercuric oxide should be activated once a week. When it is used again after a long period of suspension, it must be activated the day before. b. Gas sample measurement: After the mercuric oxide is activated, the temperature of the mercuric oxide tube is maintained at 180±1℃, and the temperature of the paper tube is maintained at 140±2℃. When measuring the gas sample, first flush the instrument with the gas sample, suck the gas sample into the measuring tube 1 from the branch a of the piston A, use 350 to 400 ml of gas sample, pass through the instrument through the tube, remove the residual gas sample from the previous gas sample, and then suck the gas sample for formal measurement. During the measurement, first insert a selenium test paper strip into the test paper tube, and after passing 50 ml of gas sample through the mercuric oxide reaction tube at a flow rate of 10±0.5 ml/min, close C, stop the airflow, take out the paper strip that has completed the reaction, and insert another selenium test paper strip, and continue to measure. For general gas samples, measure 3 strips, and for important gas samples, measure 6 strips. Measure the length of the black mark on each strip and take the arithmetic mean. After the last measurement of the day, turn off the power to cool down, and pass 40-50 ml/min of clean air through the instrument to remove the mercury vapor in the tube. After the temperature of the mercuric oxide tube drops to 100°C, stop the airflow and seal the test paper tube. 2.2.5.2 Operation of the portable measurement device
a. Activation and blank measurement of mercuric oxide: Insert the U-shaped reaction tube containing mercuric oxide into the heating device, and then put the heating device into the insulation container. The air inlet end of the U-shaped reaction tube is connected to the flowmeter and needle valve through a metal three-way valve, and clean air or pure oxygen is passed through the air inlet at a flow rate of 250-270 ml/min. Insert a concentrated selenium test strip at the outlet of the U-shaped tube to adjust the temperature regulator so that the temperature indicates 250°C, turn on the power, and start heating. After reaching the given temperature after 23 minutes, stop heating and maintain it at the given temperature. At the beginning, replace the test strip every few minutes, and then the interval between replacing the strips will be gradually lengthened. After a certain period of time, when the test strip is light gray and stable, it means that the activation of mercuric oxide has been completed. Then adjust the temperature to 180°C, and after 15-20 minutes, the blank measurement can be carried out after the temperature is constant. When measuring, first turn the three-way valve to connect the air inlet end of the U-shaped reaction tube with the flowmeter for measurement, and adjust the needle valve to allow clean air to enter the mercuric oxide tube at a flow rate of 20±1.0 ml/min. After the flow rate is adjusted, close the three-way valve, take out the concentrated test strip, insert a selenium test strip for determination (the lower end of the strip is 10 mm away from the mercuric oxide), turn the three-way valve, and immediately start the stopwatch. After 2.5 minutes of ventilation of 50 ± 2.5 ml, close the three-way valve, take out the strip, and insert another selenium test strip to continue the determination. Measure 3 strips in a row. When there is no black mark on the test strip, it is a blank qualified. Otherwise, it needs to be reactivated. b. Gas sample determination: The gas sample determination is the same as the blank determination. Connect the air inlet to the gas sample to be measured, insert a concentrated selenium test strip at the outlet of the U-shaped tube, adjust the needle valve, and ventilate the gas sample at a flow rate of 80-100 mm/min for 5-8 minutes to remove the previous gas remaining in the gas path. Then, measure 3 (or 6) strips according to the blank determination method, measure the length of the black mark, and take the arithmetic mean. After the gas sample measurement is completed, the power supply is turned off, and clean air is passed through at a flow rate of about 100 ml/min for 15 to 20 minutes, the gas line is closed, and the instrument is put away. 2.2.5.3 Measurement of black mark length
After carbon monoxide reacts with mercuric oxide, the shapes of the black marks displayed on the test strip are roughly as follows (Figure 4). Figure 4 Schematic diagram of black mark shape
When measuring the mark length, place the test strip on the ruler and carefully observe the orthogonal dividing lines of the black and light parts of the black mark on the test strip. Except for shape a, other shapes can be estimated to make the protruding black mark area sufficient to compensate for the concave area, and then converted to orthogonal to determine the orthogonal dividing line. The length of the light tail line of the orthogonal dividing line can be halved and added to the length of the black mark when measuring. The black marks on both sides of the selenium paper strip need to be measured. 2.2.6 Result processing
MT 137.1-86
2.2.6.1 The black mark measurement is read to 0.5 mm. The average value is rounded to the nearest decimal place. 2.2.6.2 Substitute the measured average black mark length into the test paper calibration formula to calculate the concentration of carbon monoxide in the gas sample. The calculated value is rounded to the nearest decimal place, and after rounding according to the digital rounding rules, it is reported as an integer. Note: The test paper calibration formula is provided by the manufacturer. 2.3 Gas chromatography
2.3.1 Principle of the method: After the gas sample is separated by the chromatographic column in the hydrogen flow, it enters the converter filled with nickel catalyst, and carbon monoxide reacts with hydrogen to convert into methane, which is measured by a hydrogen flame ionization detector. The measurement range of this method is 0~100ppm and 0~1000ppm, with sensitivities of 0.5ppm and 5ppm respectively.
2.3.2 Apparatus: A gas chromatograph with a hydrogen flame ionization detector and a carbon monoxide converter. The measurement process is shown in Figure 5. 08
TDX -01 chromatographic column
rotating furnace
large reading
quantitative
monogas H
chlorine N,
2.3.3 Determination reference conditions
pressure stabilizationwww.bzxz.net
pressure bag
needle valve
sugar pressure
spring pressure
Figure 5 Schematic diagram of chromatographic determination process
Chromatographic column: inner diameter 3 mm, length 1.mm stainless steel tube, filled with 60-80 mesh TDX-0 1 (carbon molecular sieve), column temperature 50℃; detection chamber temperature: 120℃
Conversion column: 3mm inner diameter, 250mm long U-shaped stainless steel tube, with catalyst inside, column temperature 360℃, column front pressure: 1.9kg/cm*,
Carrier gas hydrogen flow plate: 42ml/min:
Auxiliary gas air flow: 600ml/min, auxiliary gas nitrogen flow: 34ml/min,
Injection volume: 1ml,
Recording paper speed: 300mm/h.
2.3.4 Determination operation
a. When the instrument is stable, connect the calibration gas sample to the six-way valve of the process system (Figure 5), use a 1 ml quantitative tube, flush the sample inlet gas line with the calibration gas sample, turn the six-way valve to allow the calibration gas sample to enter the chromatographic column and conversion column, measure the chromatographic peak height (continuously measure 3 times, 590
MT 137.1—86
take the arithmetic average), divide the carbon monoxide concentration by the peak height to obtain the quantitative correction value. b. According to the above steps, under the same measurement conditions, allow the gas sample to be measured to enter the chromatographic column and conversion column, and measure the chromatographic peak height. 2.3.5 Result calculation
Where: C—-
Carbon monoxide concentration in the gas sample, ppm,
h—Gas sample chromatographic peak height, mm!
-Quantitative correction value.
2.3.6 Processing of measurement results
2.8.6.1 Each gas sample is measured twice. When the allowable difference of the measured values meets the requirements of Table 3, the arithmetic mean is taken as the measurement result. Otherwise, a third measurement shall be carried out and the arithmetic mean of the two measured values within the allowable difference is taken. Table 3 Allowable difference of chromatographic determination
Measurement range, ppm
0~100
0~1000
2.3.6.2 Selection of average value
Measurement value, Ppm
10 ~ 50
100~500
Allowable difference, ppm
When the measurement range is 0~100ppm, the average value is calculated to two decimal places and the decimal place is rounded off according to the number rounding rules. When the measurement range is 0~1000ppm, the average value is calculated to one decimal place and the integer is rounded off according to the number rounding rules. Additional Notes:
This standard was proposed by the Fushun Research Institute of the Coal Research Institute. This standard was drafted by the Fushun Research Institute of the Coal Research Institute and the Hebi Mining Bureau. The main drafters of this standard are Yang Wenzheng, Chen Xingye, Ye Zhanying, Zhou Jicong, and Chang Shuhua. 5912 Operation of portable measuring device
a. Activation of mercuric oxide and blank determination: Insert the U-shaped reaction tube containing mercuric oxide into the heating device, and then put the heating device into the heat preservation container. The air inlet end of the U-shaped reaction tube is connected to the flow meter and needle valve through a metal three-way valve, and clean air or pure oxygen is passed through the air inlet at a flow rate of 250-270 ml/min. Insert a concentrated selenium test paper strip at the outlet of the U-shaped tube to adjust the temperature regulator so that the temperature indicates 250℃, turn on the power, and start heating. After reaching the given temperature after 23 minutes, stop heating and maintain it at the given temperature. Start to replace the test strip every few minutes, and then the interval between replacing the strips will be gradually lengthened. After a certain period of time, when the test strip is light gray and stable, it means that the activation of mercuric oxide has been completed. Then adjust the temperature to 180℃, and after 15-20 minutes, the blank determination can be carried out after the temperature is constant. During the measurement, first turn the three-way valve to connect the air inlet end of the U-shaped reaction tube to the flow meter for measurement, and adjust the needle valve to allow clean air to enter the mercuric oxide tube at a flow rate of 20 ± 1.0 ml/min. After the flow rate is adjusted, close the three-way valve, take out the concentrated test strip, insert a selenium test strip for measurement (the lower end of the strip is 10 mm away from the mercuric oxide), turn the three-way valve, and immediately start the stopwatch. After 2.5 minutes of ventilation of 50 ± 2.5 ml, close the three-way valve, take out the strip, and insert another selenium test strip to continue the measurement. Measure 3 strips continuously. When there is no black mark on the test strip, it is a blank qualified, otherwise, it needs to be reactivated. b. Gas sample measurement: Gas sample measurement is the same as blank measurement. Connect the air inlet to the gas sample to be measured, insert a concentrated selenium test strip at the outlet of the U-shaped tube, and adjust the needle valve to ventilate the gas sample at a flow rate of 80-100 mm/min for 5-8 minutes to remove the previous gas remaining in the gas path. Then, measure 3 (or 6) strips according to the blank determination method, measure the length of the black mark, and take the arithmetic mean. After the gas sample is determined, turn off the power supply, pass clean air at a flow rate of about 100 ml/min for 15 to 20 minutes, close the gas line, and put the instrument away. 2.2.5.3 Measurement of black mark length
After carbon monoxide reacts with mercuric oxide, the shapes of the black marks displayed on the test strip are roughly as follows (Figure 4). Figure 4 Schematic diagram of black mark shape
When measuring the mark length, put the test strip on the ruler and carefully observe the orthogonal dividing lines of the black and light colors of the black marks on the test strip. Except for shape a, other shapes can be estimated to make the protruding black mark area sufficient to compensate for the concave area, and converted to orthogonal to determine the orthogonal dividing line. The length of the light tail line of the orthogonal dividing line can be halved and added to the length of the black mark when measuring. The black marks on both sides of the selenium paper strip need to be measured. 2.2.6 Result processing
MT 137.1-86
2.2.6.1 The black mark measurement is read to 0.5 mm. The average value is taken to the decimal place. 2.2.6.2 Substitute the measured average black mark length into the test paper calibration formula to calculate the concentration of carbon monoxide in the gas sample. The calculated value is rounded to the decimal place, and after rounding according to the number rounding rules, it is reported as an integer. Note: The test paper calibration formula is provided by the manufacturer. 2.3 Gas chromatography
2.3.1 Principle of the method: After the gas sample is separated by the chromatographic column in the hydrogen flow, it enters the converter filled with nickel catalyst, and carbon monoxide reacts with hydrogen to convert into methane, which is measured by hydrogen flame ionization detector. The measurement range of this method is 0~100ppm and 0~1000ppm, and the sensitivity is 0.5ppm and 5ppm respectively.
2.3.2 Apparatus: A gas chromatograph with a hydrogen flame ionization detector and a carbon monoxide converter. The determination process is shown in Figure 5. 08
TDX-01 chromatographic column
Rotating furnace
Datongyue
Quantitative
Monogas H
Chlorine N,
2.3.3 Determination reference conditions
Stable pressure
Pressure bag
Needle valve
Sugar pressure
Spring pressure
Figure 5 Schematic diagram of the chromatographic determination process
Chromatographic column: 3 mm inner diameter, 1.5 mm long stainless steel tube, filled with 60-80 mesh TDX-0 1 (carbon molecular sieve), column temperature 50℃; detection chamber temperature: 120℃
Conversion column: 3mm inner diameter, 250mm long U-shaped stainless steel tube, with catalyst inside, column temperature 360℃, column front pressure: 1.9kg/cm*,
Carrier gas hydrogen flow plate: 42ml/min:
Auxiliary gas air flow: 600ml/min, auxiliary gas nitrogen flow: 34ml/min,
Injection volume: 1ml,
Recording paper speed: 300mm/h.
2.3.4 Determination operation
a. When the instrument is stable, connect the calibration gas sample to the six-way valve of the process system (Figure 5), use a 1 ml quantitative tube, flush the sample inlet gas line with the calibration gas sample, turn the six-way valve to allow the calibration gas sample to enter the chromatographic column and conversion column, measure the chromatographic peak height (continuously measure 3 times, 590
MT 137.1—86
take the arithmetic average), divide the carbon monoxide concentration by the peak height to obtain the quantitative correction value. b. According to the above steps, under the same measurement conditions, allow the gas sample to be measured to enter the chromatographic column and conversion column, and measure the chromatographic peak height. 2.3.5 Result calculation
Where: C—-
Carbon monoxide concentration in the gas sample, ppm,
h—Gas sample chromatographic peak height, mm!
-Quantitative correction value.
2.3.6 Processing of measurement results
2.8.6.1 Each gas sample is measured twice. When the allowable difference of the measured values meets the requirements of Table 3, the arithmetic mean is taken as the measurement result. Otherwise, a third measurement shall be carried out and the arithmetic mean of the two measured values within the allowable difference is taken. Table 3 Allowable difference of chromatographic determination
Measurement range, ppm
0~100
0~1000
2.3.6.2 Selection of average value
Measurement value, Ppm
10 ~ 50
100~500
Allowable difference, ppm
When the measurement range is 0~100ppm, the average value is calculated to two decimal places and the decimal place is rounded off according to the number rounding rules. When the measurement range is 0~1000ppm, the average value is calculated to one decimal place and the integer is rounded off according to the number rounding rules. Additional Notes:
This standard was proposed by the Fushun Research Institute of the Coal Research Institute. This standard was drafted by the Fushun Research Institute of the Coal Research Institute and the Hebi Mining Bureau. The main drafters of this standard are Yang Wenzheng, Chen Xingye, Ye Zhanying, Zhou Jicong, and Chang Shuhua. 5912 Operation of portable measuring device
a. Activation of mercuric oxide and blank determination: Insert the U-shaped reaction tube containing mercuric oxide into the heating device, and then put the heating device into the heat preservation container. The air inlet end of the U-shaped reaction tube is connected to the flow meter and needle valve through a metal three-way valve, and clean air or pure oxygen is passed through the air inlet at a flow rate of 250-270 ml/min. Insert a concentrated selenium test paper strip at the outlet of the U-shaped tube to adjust the temperature regulator so that the temperature indicates 250℃, turn on the power, and start heating. After reaching the given temperature after 23 minutes, stop heating and maintain it at the given temperature. Start to replace the test strip every few minutes, and then the interval between replacing the strips will be gradually lengthened. After a certain period of time, when the test strip is light gray and stable, it means that the activation of mercuric oxide has been completed. Then adjust the temperature to 180℃, and after 15-20 minutes, the blank determination can be carried out after the temperature is constant. During the measurement, first turn the three-way valve to connect the air inlet end of the U-shaped reaction tube to the flow meter for measurement, and adjust the needle valve to allow clean air to enter the mercuric oxide tube at a flow rate of 20 ± 1.0 ml/min. After the flow rate is adjusted, close the three-way valve, take out the concentrated test strip, insert a selenium test strip for measurement (the lower end of the strip is 10 mm away from the mercuric oxide), turn the three-way valve, and immediately start the stopwatch. After 2.5 minutes of ventilation of 50 ± 2.5 ml, close the three-way valve, take out the strip, and insert another selenium test strip to continue the measurement. Measure 3 strips continuously. When there is no black mark on the test strip, it is a blank qualified, otherwise, it needs to be reactivated. b. Gas sample measurement: Gas sample measurement is the same as blank measurement. Connect the air inlet to the gas sample to be measured, insert a concentrated selenium test strip at the outlet of the U-shaped tube, and adjust the needle valve to ventilate the gas sample at a flow rate of 80-100 mm/min for 5-8 minutes to remove the previous gas remaining in the gas path. Then, measure 3 (or 6) strips according to the blank determination method, measure the length of the black mark, and take the arithmetic mean. After the gas sample is determined, turn off the power supply, pass clean air at a flow rate of about 100 ml/min for 15 to 20 minutes, close the gas line, and put the instrument away. 2.2.5.3 Measurement of black mark length
After carbon monoxide reacts with mercuric oxide, the shapes of the black marks displayed on the test strip are roughly as follows (Figure 4). Figure 4 Schematic diagram of black mark shape
When measuring the mark length, put the test strip on the ruler and carefully observe the orthogonal dividing lines of the black and light colors of the black marks on the test strip. Except for shape a, other shapes can be estimated to make the protruding black mark area sufficient to compensate for the concave area, and converted to orthogonal to determine the orthogonal dividing line. The length of the light tail line of the orthogonal dividing line can be halved and added to the length of the black mark when measuring. The black marks on both sides of the selenium paper strip need to be measured. 2.2.6 Result processing
MT 137.1-86
2.2.6.1 The black mark measurement is read to 0.5 mm. The average value is taken to the decimal place. 2.2.6.2 Substitute the measured average black mark length into the test paper calibration formula to calculate the concentration of carbon monoxide in the gas sample. The calculated value is rounded to the decimal place, and after rounding according to the number rounding rules, it is reported as an integer. Note: The test paper calibration formula is provided by the manufacturer. 2.3 Gas chromatography
2.3.1 Principle of the method: After the gas sample is separated by the chromatographic column in the hydrogen flow, it enters the converter filled with nickel catalyst, and carbon monoxide reacts with hydrogen to convert into methane, which is measured by hydrogen flame ionization detector. The measurement range of this method is 0~100ppm and 0~1000ppm, and the sensitivity is 0.5ppm and 5ppm respectively.
2.3.2 Apparatus: A gas chromatograph with a hydrogen flame ionization detector and a carbon monoxide converter. The determination process is shown in Figure 5. 08
TDX-01 chromatographic column
Rotating furnace
Datongyue
Quantitative
Monogas H
Chlorine N,
2.3.3 Determination reference conditions
Stable pressure
Pressure bag
Needle valve
Sugar pressure
Spring pressure
Figure 5 Schematic diagram of the chromatographic determination process
Chromatographic column: 3 mm inner diameter, 1.5 mm long stainless steel tube, filled with 60-80 mesh TDX-0 1 (carbon molecular sieve), column temperature 50℃; detection chamber temperature: 120℃
Conversion column: 3mm inner diameter, 250mm long U-shaped stainless steel tube, with catalyst inside, column temperature 360℃, column front pressure: 1.9kg/cm*,
Carrier gas hydrogen flow plate: 42ml/min:
Auxiliary gas air flow: 600ml/min, auxiliary gas nitrogen flow: 34ml/min,
Injection volume: 1ml,
Recording paper speed: 300mm/h.
2.3.4 Determination operation
a. When the instrument is stable, connect the calibration gas sample to the six-way valve of the process system (Figure 5), use a 1 ml quantitative tube, flush the sample inlet gas line with the calibration gas sample, turn the six-way valve to allow the calibration gas sample to enter the chromatographic column and conversion column, measure the chromatographic peak height (continuously measure 3 times, 590
MT 137.1—86
take the arithmetic average), divide the carbon monoxide concentration by the peak height to obtain the quantitative correction value. b. According to the above steps, under the same measurement conditions, allow the gas sample to be measured to enter the chromatographic column and conversion column, and measure the chromatographic peak height. 2.3.5 Result calculation
Where: C—-
Carbon monoxide concentration in the gas sample, ppm,
h—Gas sample chromatographic peak height, mm!
-Quantitative correction value.
2.3.6 Processing of measurement results
2.8.6.1 Each gas sample is measured twice. When the allowable difference of the measured values meets the requirements of Table 3, the arithmetic mean is taken as the measurement result. Otherwise, a third measurement shall be carried out and the arithmetic mean of the two measured values within the allowable difference is taken. Table 3 Allowable difference of chromatographic determination
Measurement range, ppm
0~100
0~1000
2.3.6.2 Selection of average value
Measurement value, Ppm
10 ~ 50
100~500
Allowable difference, ppm
When the measurement range is 0~100ppm, the average value is calculated to two decimal places and the decimal place is rounded off according to the number rounding rules. When the measurement range is 0~1000ppm, the average value is calculated to one decimal place and the integer is rounded off according to the number rounding rules. Additional Notes:
This standard was proposed by the Fushun Research Institute of the Coal Research Institute. This standard was drafted by the Fushun Research Institute of the Coal Research Institute and the Hebi Mining Bureau. The main drafters of this standard are Yang Wenzheng, Chen Xingye, Ye Zhanying, Zhou Jicong, and Chang Shuhua. 5913 Measurement of black mark length
After carbon monoxide reacts with mercuric oxide, the shapes of the black marks displayed on the test paper strip are roughly as follows (Figure 4). Figure 4 Schematic diagram of black mark shape
When measuring the mark length, place the test paper strip on the ruler and carefully observe the orthogonal dividing lines of the black and light parts of the black mark on the test paper strip. Except for shape a, other shapes can be estimated to make the protruding black mark area sufficient to compensate for the concave area, and converted to orthogonal to determine the orthogonal dividing line. The length of the light tail line of the orthogonal dividing line can be halved and added to the black mark length when measuring. The black marks on both sides of the selenium paper strip need to be measured. 2.2.6 Result processing
MT 137.1-86
2.2.6.1 The black mark measurement is read to 0.5 mm. The average value is taken to the decimal place. 2.2.6.2 Substitute the measured average black mark length into the test paper calibration formula to calculate the carbon monoxide concentration in the gas sample. The calculated value shall be rounded to the decimal place according to the digital rounding rules and reported as an integer. Note: The calibration formula of the test paper is provided by the manufacturer. 2.3 Gas chromatography
2.3.1 Principle of the method: After the gas sample is separated by the chromatographic column in the hydrogen flow, it enters the converter filled with nickel catalyst. Carbon monoxide reacts with hydrogen to convert into methane, which is measured by a hydrogen flame ionization detector. The measurement range of this method is 0~100ppm and 0~1000ppm, with a sensitivity of 0.5ppm and 5ppm respectively.
2.3.2 Apparatus: A gas chromatograph with a hydrogen flame ionization detector and a carbon monoxide converter. The measurement process is shown in Figure 5. 08
TDX -01 chromatographic column
rotating furnace
large reading
quantitative
monogas H
chlorine N,
2.3.3 Determination reference conditions
pressure stabilization
pressure bag
needle valve
sugar pressure
spring pressure
Figure 5 Schematic diagram of chromatographic determination process
Chromatographic column: inner diameter 3 mm, length 1.mm stainless steel tube, filled with 60-80 mesh TDX-0 1 (carbon molecular sieve), column temperature 50℃; detection chamber temperature: 120℃
Conversion column: 3mm inner diameter, 250mm long U-shaped stainless steel tube, with catalyst inside, column temperature 360℃, column front pressure: 1.9kg/cm*,
Carrier gas hydrogen flow plate: 42ml/min:
Auxiliary gas air flow: 600ml/min, auxiliary gas nitrogen flow: 34ml/min,
Injection volume: 1ml,
Recording paper speed: 300mm/h.
2.3.4 Determination operation
a. When the instrument is stable, connect the calibration gas sample to the six-way valve of the process system (Figure 5), use a 1 ml quantitative tube, flush the sample inlet gas line with the calibration gas sample, turn the six-way valve to allow the calibration gas sample to enter the chromatographic column and conversion column, measure the chromatographic peak height (continuously measure 3 times, 590
MT 137.1—86
take the arithmetic average), divide the carbon monoxide concentration by the peak height to obtain the quantitative correction value. b. According to the above steps, under the same measurement conditions, allow the gas sample to be measured to enter the chromatographic column and conversion column, and measure the chromatographic peak height. 2.3.5 Result calculation
Where: C—-
Carbon monoxide concentration in the gas sample, ppm,
h—Gas sample chromatographic peak height, mm!
-Quantitative correction value.
2.3.6 Processing of measurement results
2.8.6.1 Each gas sample is measured twice. When the allowable difference of the measured values meets the requirements of Table 3, the arithmetic mean is taken as the measurement result. Otherwise, a third measurement shall be carried out and the arithmetic mean of the two measured values within the allowable difference is taken. Table 3 Allowable difference of chromatographic determination
Measurement range, ppm
0~100
0~1000
2.3.6.2 Selection of average value
Measurement value, Ppm
10 ~ 50
100~500
Allowable difference, ppm
When the measurement range is 0~100ppm, the average value is calculated to two decimal places and the decimal place is rounded off according to the number rounding rules. When the measurement range is 0~1000ppm, the average value is calculated to one decimal place and the integer is rounded off according to the number rounding rules. Additional Notes:
This standard was proposed by the Fushun Research Institute of the Coal Research Institute. This standard was drafted by the Fushun Research Institute of the Coal Research Institute and the Hebi Mining Bureau. The main drafters of this standard are Yang Wenzheng, Chen Xingye, Ye Zhanying, Zhou Jicong, and Chang Shuhua. 5913 Measurement of black mark length
After carbon monoxide reacts with mercuric oxide, the shapes of the black marks displayed on the test paper strip are roughly as follows (Figure 4). Figure 4 Schematic diagram of black mark shape
When measuring the mark length, place the test paper strip on the ruler and carefully observe the orthogonal dividing lines of the black and light parts of the black mark on the test paper strip. Except for shape a, other shapes can be estimated to make the protruding black mark area sufficient to compensate for the concave area, and converted to orthogonal to determine the orthogonal dividing line. The length of the light tail line of the orthogonal dividing line can be halved and added to the black mark length when measuring. The black marks on both sides of the selenium paper strip need to be measured. 2.2.6 Result processing
MT 137.1-86
2.2.6.1 The black mark measurement is read to 0.5 mm. The average value is taken to the decimal place. 2.2.6.2 Substitute the measured average black mark length into the test paper calibration formula to calculate the carbon monoxide concentration in the gas sample. The calculated value shall be rounded to the decimal place according to the digital rounding rules and reported as an integer. Note: The calibration formula of the test paper is provided by the manufacturer. 2.3 Gas chromatography
2.3.1 Principle of the method: After the gas sample is separated by the chromatographic column in the hydrogen flow, it enters the converter filled with nickel catalyst. Carbon monoxide reacts with hydrogen to convert into methane, which is measured by a hydrogen flame ionization detector. The measurement range of this method is 0~100ppm and 0~1000ppm, with a sensitivity of 0.5ppm and 5ppm respectively.
2.3.2 Apparatus: A gas chromatograph with a hydrogen flame ionization detector and a carbon monoxide converter. The measurement process is shown in Figure 5. 08
TDX -01 chromatographic column
rotating furnace
large reading
quantitative
monogas H
chlorine N,
2.3.3 Determination reference conditions
pressure stabilization
pressure bag
needle valve
sugar pressure
spring pressure
Figure 5 Schematic diagram of chromatographic determination process
Chromatographic column: inner diameter 3 mm, length 1.mm stainless steel tube, filled with 60-80 mesh TDX-0 1 (carbon molecular sieve), column temperature 50℃; detection chamber temperature: 120℃
Conversion column: 3mm inner diameter, 250mm long U-shaped stainless steel tube, with catalyst inside, column temperature 360℃, column front pressure: 1.9kg/cm*,
Carrier gas hydrogen flow plate: 42ml/min:
Auxiliary gas air flow: 600ml/min, auxiliary gas nitrogen flow: 34ml/min,
Injection volume: 1ml,
Recording paper speed: 300mm/h.
2.3.4 Determination operation
a. When the instrument is stable, connect the calibration gas sample to the six-way valve of the process system (Figure 5), use a 1 ml quantitative tube, flush the sample inlet gas line with the calibration gas sample, turn the six-way valve to allow the calibration gas sample to enter the chromatographic column and conversion column, measure the chromatographic peak height (continuously measure 3 times, 590
MT 137.1—86
take the arithmetic average), divide the carbon monoxide concentration by the peak height to obtain the quantitative correction value. b. According to the above steps, under the same measurement conditions, allow the gas sample to be measured to enter the chromatographic column and conversion column, and measure the chromatographic peak height. 2.3.5 Result calculation
Where: C—-
Carbon monoxide concentration in the gas sample, ppm,
h—Gas sample chromatographic peak height, mm!
-Quantitative correction value.
2.3.6 Processing of measurement results
2.8.6.1 Each gas sample is measured twice. When the allowable difference of the measured values meets the requirements of Table 3, the arithmetic mean is taken as the measurement result. Otherwise, a third measurement shall be carried out and the arithmetic mean of the two measured values within the allowable difference is taken. Table 3 Allowable difference of chromatographic determination
Measurement range, ppm
0~100
0~1000
2.3.6.2 Selection of average value
Measurement value, Ppm
10 ~ 50
100~500
Allowable difference, ppm
When the measurement range is 0~100ppm, the average value is calculated to two decimal places and the decimal place is rounded off according to the number rounding rules. When the measurement range is 0~1000ppm, the average value is calculated to one decimal place and the integer is rounded off according to the number rounding rules. Additional Notes:
This standard was proposed by the Fushun Research Institute of the Coal Research Institute. This standard was drafted by the Fushun Research Institute of the Coal Research Institute and the Hebi Mining Bureau. The main drafters of this standard are Yang Wenzheng, Chen Xingye, Ye Zhanying, Zhou Jicong, and Chang Shuhua. 591
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