MT 445-1995 Technical Specifications for Thermal Conductivity High Concentration Methane Sensors for Coal Mines
Some standard content:
Coal Industry Standard of the People's Republic of China
Technical Conditions for High-Concentration Thermal Conductivity Methane Sensors for Coal Mines
1 Subject Content and Applicable Model
MT 445--1995
This standard specifies the technical requirements, test methods, inspection rules, marking, packaging, transportation and storage of commercial-concentration thermal conductivity methane sensors for coal mines.
This standard applies to high-concentration (0-100%) thermal conductivity methane sensors and high and low-concentration methane sensors (hereinafter referred to as sensors) used in coal mine underground environmental monitoring and combustible gas extraction, and the part of high-concentration methane measured by thermal conductivity. 2 Reference standards
GB191 Pictorial marking for packaging, storage and transportation
GB 2423. 1
GB 2423. 2
GB 2423. 4
GB 2423. 5
GB 2423.8
Basic environmental testing procedures for electric and electronic products Test A: Low temperature test method Basic environmental testing procedures for electric and electronic products Test B: High temperature test method Basic environmental testing procedures for electric and electronic products Test Db: Alternating damp heat test method Basic environmental testing procedures for electric and electronic products: Test Ea: Impact test method Basic environmental testing procedures for electric and electronic products Test Ed: Free fall test method GB 2423. 10
GB 3836. 1
GB 3836.3
Basic environmental test procedures for electrical and electronic productsTest Fc: Moving (sinusoidal) test methodGeneral requirements for explosion-proof electrical apparatus for explosive atmospheresExplosion-proof electrical apparatus for explosive atmospheresIncreased safety electrical apparatus "e"Explosion-proof electrical apparatus for explosive atmospheresIntrinsically safe circuits and electrical apparatus "i"GB/T4942.2Degrees of protection of high-voltage electrical enclosuresGB 10111
Random sampling method using random numbersMT/T 408
DC regulated power supply for coal mines
3 Technical requirements
3.1 Products shall comply with the requirements of this standard and be manufactured in accordance with the drawings and technical documents approved through the prescribed procedures. 3.2 Working conditions:
Temperature: 0~40℃;
Relative humidity: ≤98% (25℃)
Atmospheric pressure: 80~110kPa;
Wind speed: 0~8 m/s.
3.3 Storage temperature is -40~60℃.
3.4 The sensor must adopt an intrinsically safe explosion-proof structure and should comply with the relevant provisions of GB3836.1, GB3836.3 and GB3836.4.
3.5 Power supply:
Should comply with the requirements of MT/T 408.
Approved by the Ministry of Coal Industry of the People's Republic of China on March 8, 1996, and implemented on August 1, 1996
3.6 Output signal format:
The following signal format should be selected:
MT445-1995
Current: DC1~5mA (preferred), 4~20mA (load resistance 0~5000) Frequency: 5~15Hz, 200~1000Hz (pulse width greater than 0.3ms); Digital coding: transmission rate is 300, 600, 1200, 2400, 4800, 9600b/5, and the level is not less than 3V. 3.7 The sensor should have a suspension or support structure suitable for installation conditions. 3.8 The protection performance of the sensor housing should meet the IP54 protection level requirements in GB4942.2. 3.9. The cross-sectional area of the sensor cable should not be greater than 1.5nm, and the transmission distance of the sensor should not be less than 1km. 3.10 Anti-corrosion measures should be taken for the sensor housing, connectors and parts. The coating and plating should be uniform, firm and consistent in color. The printed circuit board should be coated with three-proof (anti-corrosion, anti-mildew, and moisture-proof) insulating paint at least twice. 3.11 The sensor adopts a diffusion sampling method. The sample head should be equipped with a protective cover to prevent dust and wind speed. 3.12 The sensor should indicate the measured value in percentage volume concentration. When a digital indicator is used to display the measured value, its resolution should be 1%CH4, and it can indicate the positive or negative of the indicated value.
3.13 Basic error:
The basic error of the sensor shall comply with the provisions of Table 1. Measuring range
Absolute error
Relax error
±10% Upper limit
3.14 When the load resistance of the sensor whose output signal is current changes within the range of 0~500Ω, the change of its output signal value shall not exceed the provisions of 3.13.
When the load resistance of the sensor whose output signal is frequency changes within the range of 0~～5000Ω, the change of its output signal value shall not exceed the provisions of 3.13; its pulse width shall not be less than 0.3ms. 3.15 Stability:
The basic error of the sensor working continuously for 7d shall not exceed the provisions of 3.13. 3.16 Response time:
The response time of the sensor shall not exceed 30s. 3.17 High and low concentration methane sensors The drift of the reference point of the high concentration methane sensor used in 8m/s and combustible gas extraction under the wind speed of 20m/s should not be greater than ±1%CH4. 3.18 The sensor should comply with the provisions of 3.13 during the working temperature test. 3.19 After the storage temperature test, the sensor should comply with the provisions of 3.13. 3.20 After the condensation heat test, the sensor should comply with the provisions of 3.13. 3.21 After the moving test, the connectors and parts of the sensor should not be loose or fall off, and comply with the provisions of 3.12. 3.22 After the impact test, the sensor should not be damaged, and the connectors and parts should not be loose or fall off, and comply with the provisions of 3.13. 3.23 After the drop test, the connectors and parts of the sensor should not be loose or fall off, and comply with the provisions of 3.13. 4 Test method
4.1 Environmental conditions
Unless otherwise specified in environmental tests or relevant standards, the test shall be carried out under the following environmental conditions: temperature: 15~35℃,
relative humidity: 45%~～75%;
atmospheric pressure: 86～106kPa.
4.2 Test gas samples and instruments
4.2.1 Test gas samples
MT 445—1995
Standard gas sample of methane in air (hereinafter referred to as standard gas sample), with an uncertainty of 3%. 4.2.2 Test instruments
4.2.2.1 Gas flow meter
Measuring range: 30~300mL/min; accuracy: Class 2.5. 4.2.2.2 Stopwatch
Division value: 0.01 s.
4.2.2.3 DC milliammeter
0~~100mA, 0.2 level.
4.2.2.4 Frequency meter
0～1000 kHz; Accuracy: ≤1×10-6.4.2.2.5 DC regulated power supply
Output voltage: 0～30V; Output current: 2A. 4.3 Basic error determination
The basic error determination device is shown in Figure 1. Before the determination, the instrument should be calibrated repeatedly with clean air and gas samples of the concentration specified by the manufacturer, and no adjustment should be made in subsequent determinations.
After the zero point of the instrument is stable, use the gas injection device provided by the manufacturer to sequentially introduce five standard gas samples (5, 10, 30, 50, 80)%±0.5% into the sensor according to the flow rate during calibration.
After each concentration of gas sample is passed through for 3 minutes, the indication value and output signal value (converted into methane concentration value) are read. Repeat the measurement 4 times and take the arithmetic mean of the next 3 times.
Figure 1 Schematic diagram of basic error measurement
1-test box; 2-sensor, 3-gas injection device; 4-preheating coil; 5-flow meter, 6-clean air bottle; 7-test gas sample bottle, 8-regulating valve 291
4.4 Load characteristic test
MT445--1995
4.4.1 Load characteristic test of output signal as current quantity. The difference between the output signal when the external load resistance of the sensor is 500Ω and 0Ω when it is stable in the air is converted into the methane concentration value. 4.4.2 Load characteristic test of output signal as frequency quantity. The difference between the output frequency value when the external load resistance of the sensor is 5002 and when it is short-circuited when it is stable in the air is converted into the methane concentration value. 4.5 Stability measurement
Put the adjusted sensor into the device shown in Figure 1. Run continuously for 7 days, and introduce clean air and 30% standard gas sample (5% standard gas sample for high and low concentration methane sensors) in turn at the flow rate during calibration for 3 minutes every 12 hours, and record the indicated value and output signal value. 4.6 Response time determination
The determination device is shown in Figure 2. The diffuse sampling head should use the gas injection device provided by the manufacturer. At the flow rate during calibration, pass 5% of the methane gas sample for 3 minutes and read the indication value.
Then pass clean air. After the zero point of the sensor is stable, quickly replace the gas injection device that passes the original methane gas sample at the flow rate during calibration to the sampling head, and start recording the time required for the sensor indication value to reach 90% of the original indication value. Measure 3 times and take the arithmetic mean.
Figure 2 Schematic diagram of response time determination
1-Clean air hose; 2-Clean air injection device; 3-Diffusion sampling head: 4-Sensor, 5-Exhaust port, 6-Ventilation hood support; 7-Test gas sample injection device, 8-Test gas sample hose 4.7 Wind speed effect test
Hang the sensor in the test wind tunnel and adjust the reference point of the sensor when the wind flow is zero. Then adjust the wind speed to 8 (or 20) + ° 5m/s, and artificially rotate the sensor around the hanging axis to find the position affected by the wind speed. Fix it at this position, record the indicated value once every 30s, record it 4 times in total, and take the difference between its arithmetic mean and the reference point as the displacement. 4.8 Working temperature test
The temperature of the standard gas sample introduced into the sensor during the test should be consistent with the test required temperature. 4.8.1 Low temperature working test
The temperature of the standard gas sample introduced into the sensor during the test should be consistent with the test required temperature. Perform it according to the test Ab method in GB2423.1. Under the condition of 0 ± 3℃, the sensor is powered on, and after stabilization for 2h, the basic error is measured. After that, the basic error is measured every 1h, for a total of 3 times. Take its arithmetic mean as the measured value. 4.8.2 High temperature working test
Perform it according to the test Bb method in GB2423.2. At a temperature of 40 ± 2 ° C, the sensor is powered on and stabilized for 2 hours before the basic error is measured. The basic error is measured every 1 hour thereafter, for a total of 3 times. The arithmetic mean is taken as the measured value. 4.9 Storage temperature test
4.9.1 Low temperature storage test
Performed according to the test method Ab in GB2423.1. Under the temperature of -40 ± 3 ° C, the duration is 16 hours. The sensor is not packaged, not powered, and no intermediate detection is performed. After the test, the sensor is restored to the conditions specified in 4.1 in the test chamber and maintained for 2 hours, and then the basic error is measured. 4.9.2 High temperature storage test
Performed according to the test method Bb in GB2423.2. Under the temperature of +60 ± 2 ° C, the duration is 16 hours. The sensor is not packaged, not powered, and no intermediate detection is performed. After the test, the test chamber is restored to the conditions specified in 4.1 and maintained for 2 hours, and then the basic error is measured. 4.10 Humidity test
Performed according to the test Db method in GB2423.4. The temperature is 40±2℃ and the relative humidity is 93%±3%, and the duration is 12d. The sensor is not packaged, not powered, and no intermediate detection is performed. After the test, it is restored for 2 hours under the conditions specified in 4.1, and then the basic error is measured. 4.11 Vibration test
Performed according to the test Fc method in GB2423.10. Severity level: sweep frequency range 10~~150Hz, acceleration amplitude 50m/s, vibration number 5 times. The sensor is not packaged, not powered, and no intermediate detection is performed. After the test, an appearance inspection is performed, and then the basic error is measured. 4.12 Impact test
Performed according to the test Ea method in GB2423.5. Severity level: peak acceleration is 500m/s2, pulse duration is 11±1ms, continuous impact 3 times in each direction of 3 axes (18 times in total), sensor packaging, no power, no intermediate inspection. After the test, an appearance inspection is carried out, and then the basic error is measured.
4.13 Drop test
Performed according to the test Ed method in GB2423.8. Severity level: drop height is 0.5m, free fall to a smooth and hard concrete surface in the normal use placement direction for a total of 2 times, the sensor is not packaged, no power, and no intermediate inspection is carried out. After the test, an appearance inspection is carried out, and then the basic error is measured.
4.144.9~4.13 After each test, before checking the performance, it is allowed to recalibrate the sensor. 4.15 The explosion-proof performance test method of the sensor shall be carried out by an authorized explosion-proof inspection agency in accordance with the provisions of GB3836.1, GB3836.3 and GB3836.4.
5 Inspection rules
5.1 Factory inspection
5.1.1 The quality inspection department of the manufacturer shall conduct inspection on each unit. Only after passing the inspection and issuing the certificate of conformity can the product be shipped out of the factory. 5.1.2 The factory inspection items are shown in Table 2.
5.2 Type inspection
5.2.1 Type inspection shall be conducted in any of the following situations: a.
When new products or old products are transferred to the factory for trial production and type identification; after formal production, if there are major changes in structure, materials, and processes that may affect product performance, the normal production of sensors shall be conducted once every two years;
When production is resumed after being suspended for more than two years;
When the factory inspection results are significantly different from the last type inspection; When the national quality supervision and inspection agency makes a request. Type inspection items are shown in Table 2.
Note: Indicates items that must be conducted.
MT 445--1995
Technical Development
Factory Inspection
5.2.3. Type inspection shall be conducted at the expense of the quality supervision and inspection agency designated by the Ministry of Coal Industry. Type inspection
5.2.4 Sampling:
From the sensors that have passed the factory inspection, the sampling shall be conducted according to the method specified in GB10111. The sampling base shall not be less than 10 units, and the sampling quantity shall not be less than 3 units.
5 Judgment rules:
There are 3 sensors to be inspected. During the inspection, if one of 3.13, 3.14 and 3.15 is unqualified, or two of the other items are unqualified, the batch of products shall be judged as unqualified. If one of the other items other than 3.13, 3.14 and 3.15 is unqualified, all items shall be doubled for re-inspection. If there are still unqualified items, the batch of products shall be judged as unqualified. 6 Marking, packaging, transportation and storage
6.1 Marking
6.1.1 The sensor housing should be clearly marked with "Ex", "MA" and measuring instrument markings. 6.1.2 The nameplate of the sensor should have the following information: I*
Product model and name,
Ex\ mark in the upper right corner;
Explosion-proof mark,
Explosion-proof inspection certificate number:
Coal mine safety mark number;
Manufacturing measuring instrument license number:
Related equipment model:
Main technical parameters,
Protection level;
Manufacturer name;
Factory number or date.
Packaging marking:
Shipping markings should comply with relevant transportation regulations; operating markings should comply with the provisions of GB191.
6.2 Packaging
MT445--1995
6.2.1 The packaging should be a composite protective packaging type, with rainproof, moisture-proof, dustproof and vibration-proof capabilities. 6.2.2 The following documents should be included in the packaging box:
Product certificate;
Product instruction manual;
Packing list.
6.3 Transportation
The packaged products should be suitable for road, rail, water and air transportation. 6.4 Storage
Should be stored in a well-ventilated warehouse without corrosive gases. Additional notes:
This standard was proposed by the Coal Mine Safety Standardization Technical Committee of the Ministry of Coal Industry. This standard is under the jurisdiction of the Gas Detection and Rescue Equipment Branch of the Coal Mine Safety Standardization Technical Committee of the Ministry of Coal Industry. This standard was drafted by the Fushun Branch of the China Coal Research Institute. The main drafter of this standard is Miao Yaxin.
This standard is entrusted to the Fushun Branch of the China Coal Research Institute for interpretation. 2958 Working temperature test
The temperature of the standard gas sample introduced into the sensor during the test should be consistent with the test required temperature. 4.8.1 Low temperature working test
The temperature of the standard gas sample introduced into the sensor during the test should be consistent with the test required temperature. Perform the test according to the test Ab method in GB2423.1. At a temperature of 0±3℃, the sensor is powered on, and after stabilization for 2h, the basic error is measured. Thereafter, the basic error is measured every 1h, for a total of 3 times. The arithmetic mean is taken as the measured value. 4.8.2 High temperature working test
Perform the test according to the test Bb method in GB2423.2. At a temperature of 40±2℃, the sensor is powered on, and after stabilization for 2h, the basic error is measured. Thereafter, the basic error is measured every 1h, for a total of 3 times. The arithmetic mean is taken as the measured value. 4.9 Storage temperature test
4.9.1 Low temperature storage test
Perform according to the test method Ab in GB2423.1. Under the condition of -40±3℃, the duration is 16h. The sensor is not packaged, not powered, and no intermediate detection is performed. After the test, it is restored to the conditions specified in 4.1 in the test box for 2h, and then the basic error is measured. 4.9.2 High temperature storage test
Perform according to the test method Bb in GB2423.2. Under the condition of +60±2℃, the duration is 16h. The sensor is not packaged, not powered, and no intermediate detection is performed. After the test, it is restored to the conditions specified in 4.1 in the test box for 2h, and then the basic error is measured. 4.10 Humidity test
Perform according to the test method Db in GB2423.4. Under the condition of 40±2℃ and relative humidity of 93%±3%, the duration is 12d. The sensor is not packaged, not powered, and no intermediate test is performed. After the test, it is restored for 2 hours under the conditions specified in Article 4.1, and then the basic error is measured. 4.11 Vibration test
Performed according to the test Fc method in GB2423.10. Severity level: sweep frequency range 10~~150Hz, acceleration amplitude 50m/s, vibration number 5 times. The sensor is not packaged, not powered, and no intermediate test is performed. After the test, an appearance inspection is performed, and then the basic error is measured. 4.12 Impact test
Performed according to the test Ea method in GB2423.5. Severity level: peak acceleration is 500m/s2, pulse duration is 11±1ms, 3 axes are impacted continuously in each direction 3 times (a total of 18 times), the sensor is packaged, not powered, and no intermediate test is performed. After the test, an appearance inspection is performed, and then the basic error is measured.
4.13 Drop test
Perform according to the test Ed method in GB2423.8. Severity level: Drop height is 0.5m, free fall to a smooth, hard concrete surface in the normal use direction for a total of 2 times, the sensor is not packaged, not powered, and no intermediate inspection is performed. After the test, an appearance inspection is performed, and then the basic error is measured.
4.144.9~4.13 After each test, before checking the performance, it is allowed to recalibrate the sensor. 4.15 The explosion-proof performance test method of the sensor shall be carried out by the authorized explosion-proof inspection agency in accordance with the provisions of GB3836.1, GB3836.3 and GB3836.4.
5 Inspection rules
5.1 Factory inspection
5.1.1 The quality inspection department of the manufacturer shall conduct each unit inspection, and the unit may leave the factory only after passing the inspection and issuing the certificate of conformity. 5.1.2 The factory inspection items are shown in Table 2.
5.2 Type inspection
5.2.1 Type inspection shall be conducted in any of the following cases: a.
When new products or old products are transferred to the factory for trial production and type identification; after formal production, if there are major changes in structure, materials, and processes that may affect product performance, once every two years for sensors in normal production;
When production is resumed after more than two years of suspension;
When the factory inspection results are significantly different from the last type inspection; When the national quality supervision and inspection agency makes a request. Type inspection items are shown in Table 2.
Note: Indicates items that must be conducted.
MT 445--1995
Technical Development Request
Factory Inspection
5.2.3. Type inspection shall be conducted at the expense of the quality supervision and inspection agency designated by the Ministry of Coal Industry. Type inspection
5.2.4 Sampling:
Sampling is carried out according to the method specified in GB10111 from the sensors that have passed the factory inspection. The sampling base is not less than 10 units, and the sampling quantity is not less than 3 units.
5 Judgment rules:
There are 3 sensors to be inspected. During the inspection, if one of 3.13, 3.14 and 3.15 is unqualified, or two of the other items are unqualified, the batch of products is immediately judged to be unqualified. If one of the other items other than 3.13, 3.14 and 3.15 is unqualified, all items are doubled for re-inspection. If there are still unqualified items, the batch of products is judged to be unqualified. 6 Marking, packaging, transportation, storage
6.1 Marking
6.1.1 The outer shell of the sensor should be marked with *Ex”, MA” and measuring instrument marks in an obvious place. 6.1.2 The nameplate of the sensor shall have the following contents: I*
Product model and name,
Ex\ mark in the upper right corner;
Explosion-proof mark,
Explosion-proof inspection certificate number:
Coal mine safety mark number;
Manufacturing measuring instrument license number:
Associated equipment model:
Main technical parameters,
Protection level;
Manufacturer name;
Factory number or date.
Packaging mark:
Shipping mark shall comply with relevant transportation regulations; operation mark shall comply with the provisions of GB191.
6.2 Packaging
MT445--1995
6.2.1 The packaging shall adopt composite protective packaging type, which has the ability to prevent rain, moisture, dust and vibration. 6.2.2 The following documents should be included in the packaging box:
Product certificate;
Product instruction manual;
Packing list.
6.3 Transportation
The packaged products should be suitable for transportation by road, rail, water and air. 6.4 Storage
They should be stored in a well-ventilated warehouse without corrosive gases. Additional notes:
This standard was proposed by the Coal Mine Safety Standardization Technical Committee of the Ministry of Coal Industry. This standard is under the jurisdiction of the Gas Detection and Rescue Equipment Branch of the Coal Mine Safety Standardization Technical Committee of the Ministry of Coal Industry. This standard was drafted by the Fushun Branch of the China Coal Research Institute. The main drafter of this standard is Miao Yaxin.
This standard is entrusted to the Fushun Branch of the China Coal Research Institute for interpretation. 2958 Working temperature test
The temperature of the standard gas sample introduced into the sensor during the test should be consistent with the test required temperature. 4.8.1 Low temperature working test
The temperature of the standard gas sample introduced into the sensor during the test should be consistent with the test required temperature. Perform the test according to the test Ab method in GB2423.1. At a temperature of 0±3℃, the sensor is powered on, and after stabilization for 2h, the basic error is measured. Thereafter, the basic error is measured every 1h, for a total of 3 times. The arithmetic mean is taken as the measured value. 4.8.2 High temperature working test
Perform the test according to the test Bb method in GB2423.2. At a temperature of 40±2℃, the sensor is powered on, and after stabilization for 2h, the basic error is measured. Thereafter, the basic error is measured every 1h, for a total of 3 times. The arithmetic mean is taken as the measured value. 4.9 Storage temperature test
4.9.1 Low temperature storage test
Perform according to the test method Ab in GB2423.1. Under the condition of -40±3℃, the duration is 16h. The sensor is not packaged, not powered, and no intermediate detection is performed. After the test, it is restored to the conditions specified in 4.1 in the test box for 2h, and then the basic error is measured. 4.9.2 High temperature storage test
Perform according to the test method Bb in GB2423.2. Under the condition of +60±2℃, the duration is 16h. The sensor is not packaged, not powered, and no intermediate detection is performed. After the test, it is restored to the conditions specified in 4.1 in the test box for 2h, and then the basic error is measured. 4.10 Humidity test
Perform according to the test method Db in GB2423.4. Under the condition of 40±2℃ and relative humidity of 93%±3%, the duration is 12d. The sensor is not packaged, not powered, and no intermediate test is performed. After the test, it is restored for 2 hours under the conditions specified in Article 4.1, and then the basic error is measured. 4.11 Vibration test
Performed according to the test Fc method in GB2423.10. Severity level: sweep frequency range 10~~150Hz, acceleration amplitude 50m/s, vibration number 5 times. The sensor is not packaged, not powered, and no intermediate test is performed. After the test, an appearance inspection is performed, and then the basic error is measured. 4.12 Impact test
Performed according to the test Ea method in GB2423.5. Severity level: peak acceleration is 500m/s2, pulse duration is 11±1ms, 3 axes are impacted continuously in each direction 3 times (a total of 18 times), the sensor is packaged, not powered, and no intermediate test is performed. After the test, an appearance inspection is performed, and then the basic error is measured.
4.13 Drop test
Perform according to the test Ed method in GB2423.8. Severity level: Drop height is 0.5m, free fall to a smooth, hard concrete surface in the normal use direction for a total of 2 times, the sensor is not packaged, not powered, and no intermediate inspection is performed. After the test, an appearance inspection is performed, and then the basic error is measured.
4.144.9~4.13 After each test, before checking the performance, it is allowed to recalibrate the sensor. 4.15 The explosion-proof performance test method of the sensor shall be carried out by the authorized explosion-proof inspection agency in accordance with the provisions of GB3836.1, GB3836.3 and GB3836.4.
5 Inspection rules
5.1 Factory inspection
5.1.1 The quality inspection department of the manufacturer shall conduct each unit inspection, and the unit may leave the factory only after passing the inspection and issuing the certificate of conformity. 5.1.2 The factory inspection items are shown in Table 2.
5.2 Type inspection
5.2.1 Type inspection shall be conducted in any of the following cases: a.
When new products or old products are transferred to the factory for trial production and type identification; after formal production, if there are major changes in structure, materials, and processes that may affect product performance, once every two years for sensors in normal production;
When production is resumed after more than two years of suspension;
When the factory inspection results are significantly different from the last type inspection; When the national quality supervision and inspection agency makes a request. Type inspection items are shown in Table 2.
Note: Indicates items that must be conducted.
MT 445--1995
Technical Development Request
Factory Inspection
5.2.3. Type inspection shall be conducted at the expense of the quality supervision and inspection agency designated by the Ministry of Coal Industry. Type inspection
5.2.4 Sampling:
Sampling is carried out according to the method specified in GB10111 from the sensors that have passed the factory inspection. The sampling base is not less than 10 units, and the sampling quantity is not less than 3 units.
5 Judgment rules:
There are 3 sensors to be inspected. During the inspection, if one of 3.13, 3.14 and 3.15 is unqualified, or two of the other items are unqualified, the batch of products is immediately judged to be unqualified. If one of the other items other than 3.13, 3.14 and 3.15 is unqualified, all items are doubled for re-inspection. If there are still unqualified items, the batch of products is judged to be unqualified. 6 Marking, packaging, transportation, storage
6.1 Marking
6.1.1 The outer shell of the sensor should be marked with *Ex”, MA” and measuring instrument marks in an obvious place. 6.1.2 The nameplate of the sensor shall have the following contents: I*
Product model and name,
Ex\ mark in the upper right corner;
Explosion-proof mark,
Explosion-proof inspection certificate number:
Coal mine safety mark number;
Manufacturing measuring instrument license number:
Associated equipment model:
Main technical parameters,
Protection level;
Manufacturer name;
Factory number or date.
Packaging mark:
Shipping mark shall comply with relevant transportation regulations; operation mark shall comply with the provisions of GB191.
6.2 Packaging
MT445--1995
6.2.1 The packaging shall adopt composite protective packaging type, which has the ability to prevent rain, moisture, dust and vibration. 6.2.2 The following documents should be included in the packaging box:
Product certificate;
Product instruction manual;
Packing list.
6.3 Transportation
The packaged products should be suitable for transportation by road, rail, water and air. 6.4 Storage
They should be stored in a well-ventilated warehouse without corrosive gases. Additional notes:
This standard was proposed by the Coal Mine Safety Standardization Technical Committee of the Ministry of Coal Industry. This standard is under the jurisdiction of the Gas Detection and Rescue Equipment Branch of the Coal Mine Safety Standardization Technical Committee of the Ministry of Coal Industry. This standard was drafted by the Fushun Branch of the China Coal Research Institute. The main drafter of this standard is Miao Yaxin.
This standard is entrusted to the Fushun Branch of the China Coal Research Institute for interpretation. 29510. Test Fc method is used. Severity level: sweep frequency range is 10~~150Hz, acceleration amplitude is 50m/s, and vibration number is 5 times. The sensor is not packaged, not powered, and no intermediate inspection is performed. After the test, an appearance inspection is performed, and then the basic error is measured. 4.12 Impact test
Performed according to the test Ea method in GB2423.5. Severity level: peak acceleration is 500m/s2, pulse duration is 11±1ms, and 3 axes are impacted continuously in each direction for 3 times (a total of 18 times). The sensor is packaged, not powered, and no intermediate inspection is performed. After the test, an appearance inspection is performed, and then the basic error is measured.
4.13 Drop test
Performed according to the test Ed method in GB2423.8. Severity level: drop height is 0.5m, free fall onto a smooth and hard concrete surface in the normal use direction for a total of 2 times, the sensor is not packaged, not powered, and no intermediate inspection is performed. After the test, conduct an appearance inspection and then determine the basic error.
4.144.9~4.13 After each test and before checking the performance, it is allowed to recalibrate the sensor. 4.15 The explosion-proof performance test method of the sensor shall be carried out by an authorized explosion-proof inspection agency in accordance with the provisions of GB3836.1, GB3836.3 and GB3836.4.
5 Inspection rules
5.1 Factory inspection
5.1.1 The quality inspection department of the manufacturer shall conduct inspection on each unit, and the unit may only leave the factory after passing the inspection and issuing a certificate of conformity. 5.1.2 See Table 2 for factory inspection items.
5.2 Type inspection
5.2.1 Type inspection shall be conducted in any of the following cases: a.
When new products or old products are transferred to the factory for trial production and type identification; after formal production, if there are major changes in structure, materials, and processes that may affect product performance, once every two years for sensors in normal production;
When production is resumed after more than two years of suspension;
When the factory inspection results are significantly different from the last type inspection; When the national quality supervision and inspection agency makes a request. Type inspection items are shown in Table 2.
Note: Indicates items that must be conducted.
MT 445--1995
Technical Development Request
Factory Inspection
5.2.3. Type inspection shall be conducted at the expense of the quality supervision and inspection agency designated by the Ministry of Coal Industry. Type inspection
5.2.4 Sampling:
Sampling is carried out according to the method specified in GB10111 from the sensors that have passed the factory inspection. The sampling base is not less than 10 units, and the sampling quantity is not less than 3 units.
5 Judgment rules:
There are 3 sensors to be inspected. During the inspection, if one of 3.13, 3.14 and 3.15 is unqualified, or two of the other items are unqualified, the batch of products is immediately judged to be unqualified. If one of the other items other than 3.13, 3.14 and 3.15 is unqualified, all items are doubled for re-inspection. If there are still unqualified items, the batch of products is judged to be unqualified. 6 Marking, packaging, transportation, storage
6.1 Marking
6.1.1 The outer shell of the sensor should be marked with *Ex”, MA” and measuring instrument marks in an obvious place. 6.1.2 The nameplate of the sensor shall have the following contents: I*
Product model and name,
Ex\ mark in the upper right corner;
Explosion-proof mark,
Explosion-proof inspection certificate number:
Coal mine safety mark number;
Manufacturing measuring instrument license number:
Associated equipment model:
Main technical parameters,
Protection level;
Manufacturer name;
Factory number or date.
Packaging mark:
Shipping mark shall comply with relevant transportation regulations; operation mark shall comply with the provisions of GB191.
6.2 Packaging
MT445--1995
6.2.1 The packaging shall adopt composite protective packaging type, which has the ability to prevent rain, moisture, dust and vibration. 6.2.2 The following documents should be included in the packaging box:
Product certificate;
Product instruction manual;
Packing list.
6.3 Transportation
The packaged products should be suitable for transportation by road, rail, water and air. 6.4 Storage
They should be stored in a well-ventilated warehouse without corrosive gases. Additional notes:
This standard was proposed by the Coal Mine Safety Standardization Technical Committee of the Ministry of Coal Industry. This standard is under the jurisdiction of the Gas Detection and Rescue Equipment Branch of the Coal Mine Safety Standardization Technical Committee of the Ministry of Coal Industry. This standard was drafted by the Fushun Branch of the China Coal Research Institute. The main drafter of this standard is Miao Yaxin.
This standard is entrusted to the Fushun Branch of the China Coal Research Institute for interpretation. 29510. Test Fc method is used. Severity level: sweep frequency range is 10~~150Hz, acceleration amplitude is 50m/s, and vibration number is 5 times. The sensor is not packaged, not powered, and no intermediate inspection is performed. After the test, an appearance inspection is performed, and then the basic error is measured. 4.12 Impact test
Performed according to the test Ea method in GB2423.5. Severity level: peak acceleration is 500m/s2, pulse duration is 11±1ms, and 3 axes are impacted continuously in each direction for 3 times (a total of 18 times). The sensor is packaged, not powered, and no intermediate inspection is performed. After the test, an appearance inspection is performed, and then the basic error is measured.
4.13 Drop test
Performed according to the test Ed method in GB2423.8. Severity level: drop height is 0.5m, free fall onto a smooth and hard concrete surface in the normal use direction for a total of 2 times, the sensor is not packaged, not powered, and no intermediate inspection is performed. After the test, conduct an appearance inspection and then determine the basic error.
4.144.9~4.13 After each test and before checking the performance, it is allowed to recalibrate the sensor. 4.15 The explosion-proof performance test method of the sensor shall be carried out by an authorized explosion-proof inspection agency in accordance with the provisions of GB3836.1, GB3836.3 and GB3836.4.
5 Inspection rules
5.1 Factory inspection
5.1.1 The quality inspection department of the manufacturer shall conduct inspection on each unit, and the unit may only leave the factory after passing the inspection and issuing a certificate of conformity. 5.1.2 See Table 2 for factory inspection items.
5.2 Type inspection
5.2.1 Type inspection shall be conducted in any of the following cases: a.
When new products or old products are transferred to the factory for trial production and type identification; after formal production, if there are major changes in structure, materials, and processes that may affect product performance, once every two years for sensors in normal production;
When production is resumed after more than two years of suspension;
When the factory inspection results are significantly different from the last type inspection; When the national quality supervision and inspection agency makes a request. Type inspection items are shown in Table 2.
Note: Indicates items that must be conducted.
MT 445--1995
Technical Development Request
Factory Inspection
5.2.3. Type inspection shall be conducted at the expense of the quality supervision and inspection agency designated by the Ministry of Coal Industry. Type inspection
5.2.4 Sampling:
Sampling is carried out according to the method specified in GB10111 from the sensors that have passed the factory inspection. The sampling base is not less than 10 units, and the sampling quantity is not less than 3 units.
5 Judgment rules:
There are 3 sensors to be inspected. During the inspection, if one of 3.13, 3.14 and 3.15 is unqualified, or two of the other items are unqualified, the batch of products is immediately judged to be unqualified. If one of the other items other than 3.13, 3.14 and 3.15 is unqualified, all items are doubled for re-inspection. If there are still unqualified items, the batch of products is judged to be unqualified. 6 Marking, packaging, transportation, storage
6.1 Marking
6.1.1 The outer shell of the sensor should be marked with *Ex”, MA” and measuring instrument marks in an obvious place. 6.1.2 The nameplate of the sensor shall have the following contents: I*
Product model and name,
Ex\ mark in the upper right corner;
Explosion-proof mark,
Explosion-proof inspection certificate number:
Coal mine safety mark number;
Manufacturing measuring instrument license number:
Associated equipment model:
Main technical parameters,
Protection level;
Manufacturer name;
Factory number or date.
Packaging mark:
Shipping mark shall comply with relevant transportation regulations; operation mark shall comply with the provisions of GB191.
6.2 Packaging
MT445--1995www.bzxz.net
6.2.1 The packaging shall adopt composite protective packaging type, which has the ability to prevent rain, moisture, dust and vibration. 6.2.2 The following documents should be included in the packaging box:
Product certificate;
Product instruction manual;
Packing list.
6.3 Transportation
The packaged products should be suitable for transportation by road, rail, water and air. 6.4 Storage
They should be stored in a well-ventilated warehouse without corrosive gases. Additional notes:
This standard was proposed by the Coal Mine Safety Standardization Technical Committee of the Ministry of Coal Industry. This standard is under the jurisdiction of the Gas Detection and Rescue Equipment Branch of the Coal Mine Safety Standardization Technical Committee of the Ministry of Coal Industry. This standard was drafted by the Fushun Branch of the China Coal Research Institute. The main drafter of this standard is Miao Yaxin.
This standard is entrusted to the Fushun Branch of the China Coal Research Institute for interpretation. 2954 Storage
Should be stored in a well-ventilated warehouse without corrosive gas. Additional Notes:
This standard was proposed by the Coal Mine Safety Standardization Technical Committee of the Ministry of Coal Industry. This standard is under the jurisdiction of the Gas Detection and Rescue Equipment Branch of the Coal Mine Safety Standardization Technical Committee of the Ministry of Coal Industry. This standard was drafted by the Fushun Branch of the China Coal Research Institute. The main drafter of this standard is Miao Yaxin.
This standard is entrusted to the Fushun Branch of the China Coal Research Institute for interpretation. 2954 Storage
Should be stored in a well-ventilated warehouse without corrosive gas. Additional Notes:
This standard was proposed by the Coal Mine Safety Standardization Technical Committee of the Ministry of Coal Industry. This standard is under the jurisdiction of the Gas Detection and Rescue Equipment Branch of the Coal Mine Safety Standardization Technical Committee of the Ministry of Coal Industry. This standard was drafted by the Fushun Branch of the China Coal Research Institute. The main drafter of this standard is Miao Yaxin.
This standard is entrusted to the Fushun Branch of the China Coal Research Institute for interpretation. 295
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