This standard specifies the structure, technical requirements, test methods, inspection rules and marking, packaging, transportation and storage of hydrogen detection tubes. This standard applies to long-length hydrogen detection tubes (hereinafter referred to as detection tubes). MT 276-1994 Hydrogen detection tube MT276-1994 Standard download decompression password: www.bzxz.net

Coal Industry Standard of the People's Republic of China
1 Subject content and scope of application
MT 276---94
This standard specifies the structure, technical requirements, test methods, inspection rules and marking, packaging, transportation and storage of hydrogen detection tubes. This standard applies to the comparative length hydrogen detection tube (hereinafter referred to as the detection tube). 2 Reference standards
GB7230 Gas detection tube device
GB 10111 Method for random sampling using random numbers 3 Structure
3.1 The structure of the detection tube is shown in Figure 1:
Figure 1 Schematic diagram of hydrogen detection tube
1-tube tip; 2-starting end lining plug, 3-protective layer; 4-interference removal layer; 5-catalytic layer; 6-indicator powder; 7-glass tube; 8-lining plug
3.2 The measurement range of the detection tube is 0.5%~3%, and the minimum graduation value is 0.5%. 4 Technical requirements
4.1 The interfaces of each layer of the filling material of the test tube should be neat. 4.2 The graduation line of the test tube should be clear and firm. 4.3 The length difference of each box of test tubes should not exceed 5mm4.4 The distance between the liner plug at the starting end of the test tube and the tip of the tube should not be less than 5mm. The difference between the longest and shortest ends of the interface between the isolation layer and the indicator powder along the longitudinal direction of the tube wall should not exceed 1 mm. 4.5F
4:6 After the measurement, the difference between the longest and shortest ends of the interface between the discolored part and the undiscolored part of the indicator powder along the longitudinal direction of the tube wall should not exceed 20% of the average value of the two.
After the drop test, the filling material of the test tube should be tight, and there should be no gap between the liner plug and the protective layer. 4.7
The minimum detection concentration of the test tube is 0.3%. 4.8
The precision (CV) of the test tube is less than or equal to 10%. 4.9
4.10 The accuracy of the test tube at room temperature shall comply with the provisions of Table 1. Approved by the Ministry of Energy of the People's Republic of China on May 1, 1992
Implemented on October 1, 1994
Detection scope
4.11 The validity period of the test tube shall be no less than 1 year. MT 276 -- 94
Relative error of the measured value
Accuracy
4.12 The test tube must be used in conjunction with a special sampler that meets the requirements of Article 3.2 of GB7230. 5 Test method
5.14.1 and 4.2 shall be checked by sensory organs.
5.24.3 to 4.6 shall be measured with a steel ruler with a graduation value of 0.5 mm. Relative error of the average value of the measured value
5.3 Drop test
Randomly select 10 test tubes from the sample for drop test. During the test, the starting end of the test tube is tied downward into a bundle, and it is freely dropped from a height of 25mm to a 5mm thick rubber plate 10 times, and then its internal filling is checked. 5.4 Minimum detection concentration test
Randomly select 10 test tubes from the sample, use a standard gas sample with a concentration of 0.3%±0.5%, and test it at room temperature according to the method specified in the instruction manual to check whether the color change is obvious. The uncertainty of the standard gas sample is ±3% (the same below). 5.5 Precision and accuracy test
Randomly select 20 test tubes from the sample, use the standard gas sample specified in Table 2, and repeat the test 10 times for each concentration of standard gas sample at room temperature according to the method specified in the instruction manual. The measured value of the detection tube is calculated according to formula (1):
Where: X -
-measured value of the detection tube, %
measured value of the color change length of the indicator powder, mm
concentration of the detection tube graduation line close to the standard gas sample concentration, %, L, the length from the starting end of the detection tube graduation line to the graduation line close to the standard gas sample concentration, mm. The precision of the detection tube is calculated according to formula (2):
CV(%)=× 100
standard deviation:
Where:
Xthe average value of the detection tube measured value, %.
The accuracy of the detection tube is calculated according to formula (3) and formula (4): A
Where: A1
relative error of the measured value, %;
relative error of the average value of the measured value, %;
measured value of the detection tube, %.
Average value of the test tube measurement value, %
Concentration of standard gas sample, %.
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(2)
5.6 Test data processing
Test scope
MT 276—94
5.6.1 When calculating the test tube measurement value, the significant figures are retained to 1 decimal place. Standard gas sample concentration
5.6.2 When calculating the precision and accuracy of the test tube, calculate to two decimal places and round to 1 decimal place. 6 Inspection rules
Products are divided into factory inspection and type inspection
6.1 Factory inspection
6.1.1 Products shall be inspected by the factory quality inspection department. They can only be shipped after passing the inspection and issuing a certificate of conformity. 6.1.2 Each batch of products shipped shall be subject to factory inspection. The factory inspection items include 4.1 to 4.10. 6.2 Type inspection
6.2.1 Type inspection should be carried out in any of the following situations: a.
When the new product or old product is transferred to the factory for trial production and identification; after formal production, if there are major changes in structure, materials, and processes that may affect product performance; during normal production, an inspection should be carried out every year; when production is resumed after one year of suspension;
When the factory inspection results are significantly different from the last type inspection; when the national quality supervision agency proposes a type inspection requirement. f.
Type inspection items include 4.1 to 4.10. 6.2.2
6.3 Sampling
6.3.1 Sampling for factory inspection
150 pieces should be drawn from the same batch of products that have been packaged into boxes and are ready to be shipped, in units of boxes according to the method specified in GB10111. 6.3.2 Sampling for type inspection
150 tubes shall be taken from the qualified products after factory inspection in accordance with the method specified in GB10111. %
6.3.3 Randomly select 3 boxes from the sample for inspection in 4.3, then randomly select 10 tubes from each box for inspection in 4.1, 4.2, 4.4, and 4.5; randomly select 10 tubes for inspection in 4.7; randomly select 10 tubes for inspection in 4.8; randomly select 20 tubes for inspection in 4.9 and 4.10; then use the tubes used for testing higher concentration accuracy to test 4.6. 6.4 Judgment rules
6.4.1 For 4.3, if 2 boxes fail to meet the requirements, it will be judged as unqualified. 6.4.2 For 4.1, 4.2, 4.4, and 4.5, if 3 test tubes fail to meet the requirements, they will be judged as unqualified. 6.4.3 For 4.6 and 4.7, if 2 test tubes fail to meet the requirements, they will be judged as unqualified. 6.4.4 For 4.8, if 2 test tubes fail to meet the requirements, they will be judged as unqualified; if 1 test tube fails to meet the requirements, the number of test tubes should be doubled for re-testing. If the requirements are still not met, it will be judged as unqualified. 6.4.5 For 4.9, if the requirements are not met, it will be judged as unqualified. 6.4.6 For 4.10, if both items fail to meet the requirements, it will be judged as unqualified; if 1 item fails to meet the requirements, the number of test tubes should be doubled for re-testing. If the requirements are still not met, it will be judged as unqualified. 7 Marking, packaging, transportation and storage
7.1 Marking
Indicators
7.1.1 Product marking
The markings on each test tube shall include:
Measuring instrument marking;
b. Trademark;
c. Batch number.
7.1.2 Packaging marking
The markings on the packaging box of the test tube shall include: a. Manufacturer's name:
Product name and model,
Quantity: Www.bzxZ.net
Trademark;
Batch number:
Validity period:
Manufacturing measuring instrument license number,
Instrument and meter inspection certificate number;
Safety mark and its number.
MT 276.- 94
The packaging box should have the signs of "fragile" and "handle with care". Packaging
Test tubes should be packed in a hard box according to a certain number and fixed with soft objects. They should not be moved. The box should contain the instruction manual and product certificate.
7.3 Transportation
Avoid dropping or smashing the tubes during shipment and ship them as fragile items. 7:4 Storage
The test tube should be stored in a room at room temperature and in a dry place, and should be strictly protected from sunlight. Additional remarks:
This standard was proposed by China Coal Research Institute. This standard is under the jurisdiction of Fushun Branch of China Coal Research Institute. This standard was jointly drafted by Fushun Branch of China Coal Research Institute and Hebi Mining Bureau. The main drafters of this standard are Yang Wenzheng, Chen Xingye and Ye Zhanying. This standard is entrusted to Fushun Branch of China Coal Research Institute for interpretation. 172
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