This standard specifies the technical requirements, test methods, inspection rules, marking, packaging, transportation and storage of temperature sensors. This standard applies to temperature sensors for coal mines and other mine temperature sensors (hereinafter referred to as sensors). MT 381-1995 General Technical Requirements for Mine Temperature Sensors MT381-1995 Standard download decompression password: www.bzxz.net

Coal Industry Standard of the People's Republic of China
General Technical Conditions for Mine Temperature Sensors
1 Subject Content and Scope of Application
MT 381-1995
This standard specifies the technical requirements, test methods, inspection rules, marking, packaging, transportation and storage of temperature sensors. This standard applies to temperature sensors for coal mines and also to temperature sensors for other mines (hereinafter referred to as sensors). 2 Reference Standards
Packaging, Storage and Transportation Pictorial Marking
GB 191
GB1410 Test methods for volume resistivity and surface resistivity of solid insulating materials GB2423.1 Basic environmental test procedures for electric and electronic products Test A: Low temperature test method GB2423.2 Basic environmental test procedures for electric and electronic products Test B: High temperature test method GB2423.4 Basic environmental test procedures for electric and electronic products Test Db: Alternating damp heat test method Basic environmental test procedures for electric and electronic products Test Ea: Impact test method GB2423.5
GB2423. 10 Basic environmental test procedures for electrical and electronic products Test Fc: Vibration (sinusoidal) test method GB3836.1 General requirements for explosion-proof electrical equipment for explosive atmospheres Explosion-proof electrical equipment for explosive atmospheres Intrinsically safe circuits and electrical equipment "" GB3836.4
GB4942.2 Protection level of low-voltage electrical enclosures GB10111 Random sampling method using random numbers 3 Technical requirements
3.1 The sensor shall comply with the provisions of this standard and be manufactured according to the drawings and technical documents approved by the prescribed procedures. 3.2 The sensor shall adopt an intrinsically safe explosion-proof structure and shall comply with the relevant provisions of GB3836.1 and GB3836.4. 3.3 The sensor shall work normally under the following environmental conditions Ambient temperature: 0~40℃;
b. Relative humidity: <100%;
Atmospheric pressure: 86~106kpa.
3.4 ​​General requirements
3.4.1 The sensor surface should not have obvious scratches, the shell surface coating should be firm, the metal parts should not be rusted and deformed, and the connectors should be tightened.
3.4.2 The structure of the sensor should ensure the convenience and reliability of debugging, maintenance and installation. The sensor should be equipped with a structure that is convenient for hanging or supporting. 3.4.3 The protection performance of the sensor shell should comply with the provisions of GB4942.2IP54. 3.4.4 Stainless steel should be preferred as the material of the sensor shell. When a plastic shell is used, its surface insulation resistance should not be greater than 1×10°03.5 Main components and assemblies
3.5.1 The components of the sensor should be clean and free of corrosion; the printed circuit board and wiring device should be firmly installed; the solder joints on the circuit should be beautiful and free of cold solder joints; the printed circuit board should be coated with two coats of insulating paint. 3.5.2 The electrical clearance and creepage distance of the intrinsically safe circuit of the sensor shall comply with the provisions of Article 4.6 of GB3836.4 Approved by the Ministry of Coal Industry of the People's Republic of China on January 25, 1995 220
Implementation on May 1, 1995
3.5.3 The sensor shall preferably use a digital display. MT 381-1995
3.5.4 The maximum allowable surface temperature of the sensor's electrical components shall not exceed +150℃. 3.6 Main electrical performance
3.6.1 The sensor shall be able to work normally under the conditions of a power supply voltage of 24, 18, 15, 12V (dc). 3.6.2 The maximum operating current of the sensor shall not exceed 200mA (dc). 3.6.3 The transmission distance from the sensor to the substation and power box shall not be less than 1km. 3.6.4 The output analog signal of the sensor shall comply with the following signal standards: a.
DC analog signal 1~～5mA, preferred; DC analog signal
4～20mA, only for ground;
DC analog signal 0～5V;
Frequency analog signal 200～1000Hz (positive and negative pulse widths shall not be less than 0.3ms), preferred. 3.7 After the working stability test, the electrical performance of the sensor shall comply with the provisions of Article 3.6 of this standard. 3.8 After the high temperature and low temperature test under working conditions, the appearance and electrical performance of the sensor shall comply with the provisions of Articles 3.4.1 and 3.6 of this standard.
3.9 After the high temperature and low temperature storage and transportation test under non-working conditions, the appearance and electrical performance of the sensor shall comply with the provisions of Articles 3.4.1 and 3.6 of this standard.
3.10 After the vibration test in the non-working state, the sensor shall comply with the provisions of Article 3.4.1, Article 3.5.1 and Article 3.6 of this standard.
1 After the impact test in the non-working state, the appearance and electrical performance of the sensor shall comply with the provisions of Article 3.4.1 and Article 3.6 of this standard.
3.12 After the alternating damp heat test in the non-working state, the sensor shall comply with the following provisions: a.
The insulation resistance between the live circuit and the shell shall not be less than 1MQ. b.
The live circuit and the outside shall be able to withstand a 50Hz, 500V voltage withstand test. c.
The appearance and electrical performance shall comply with the provisions of Article 3.4.1 and Article 3.6 of this standard. 4 Test method
4.1 Test conditions
Temperature: 15~35℃;
b. Output load resistance: 500Ω;
Test can only be carried out after the power supply is turned on for 30 minutes.
4.2 Instruments and equipment
4.2.1 The allowable error of the measuring instrument should not be greater than 1/3 of the allowable error of the sensor. 4.2.2 DC regulated power supply
Output voltage: The adjustable range should meet the requirements of the sensor power supply voltage of 12~24V (dc); output current: should not be less than 300mA.
4.3 Test steps
4.3.1 The appearance is inspected by visual inspection.
4.3.2 The protective performance of the shell is tested in accordance with the provisions of Chapter 5 and Chapter 6 of GB4942.2. 4.3.3 The surface insulation resistance of the plastic shell is measured in accordance with the provisions of Articles 15 and 16 of GB1410. 4.3.4 The surface temperature of electrical components shall be measured in accordance with the provisions of Article 24.1 of GB3836.1. 4.3.5 Main electrical performance test
Connect 1km simulation cable and measuring instrument between the sensor and the power box and the substation respectively, and test the main electrical performance of the sensor in the working state. bzxz.net
MT 381-1995
4.3.6 The explosion-proof performance of the sensor shall be tested in accordance with the provisions of GB3836.1 and GB3836.4. 4.3.7 Working stability test
The sensor shall be powered on for no less than 2d, and measured 4 times, with a time interval of no more than 12h. 4.3.8 The ambient temperature test of the working state shall be carried out in accordance with the provisions of GB2423.1 Test Ab and GB2423.2 Test Bb. a.
Severity level: low temperature 0℃, high temperature 40℃, duration 2h; b. Use temperature gradient test method.
4.3.9 Storage and transportation environment temperature test under non-working conditions 4.3.9.1 Low temperature test shall be carried out in accordance with the provisions of GB2423.1 Test Ab. a.
Severity level: temperature -20±3℃, duration 16h; temperature gradient test method;
After the test, place at room temperature for 2 h.
4.3.9.2 High temperature test shall be carried out in accordance with the provisions of GB2423.2 Test Bb. a.
Severity level: temperature 50±3℃, duration 16h; temperature gradient test method;
After the test, place at room temperature for 2 h.
Impact test shall be carried out in accordance with the provisions of GB2423.5 4.3. 10
Severity level: peak acceleration is 50g, pulse duration is 11ms; test samples are not packaged and no intermediate testing is performed. The vibration test is carried out in accordance with the provisions of GB2423.10. 4.3.11
Severity: sweep frequency range 10～150Hz, acceleration 2g, sweep cycle number 5 times on each axis; a.
The test sample is not packaged and no intermediate inspection is carried out. b.
After completing the tests of Articles 4.3.9, 4.3.10 and 4.3.11 of this standard, it is allowed to recalibrate the sensor and carry out electrical performance tests in accordance with Article 4.3.5 of this standard.
4.3.12 Alternating damp heat test is carried out in accordance with the method specified in GB2423.4. a.
Severity: Maximum temperature 40±2℃;
Test cycle 6d (main electrical performance test cycle 2d). b. After the test, place it at room temperature for 2 hours to remove surface moisture. 5 Inspection rules
5.1 Factory inspection
5.1.1 Products shall be inspected unit by unit by the quality inspection department of the manufacturer, and may only leave the factory after passing the inspection and issuing a certificate of conformity. 5.1.2 Products shall be inspected according to the items specified in Table 1. 5.2 Type inspection
5.2.1. Type inspection shall be carried out in any of the following circumstances: a.
Trial production and identification of new products or old products transferred to the factory for production; after formal production, if there are major changes in structure, materials, and processes that may affect product performance; during normal production, inspection shall be carried out every five years; when production is resumed after a long period of suspension; when there is a significant difference between the factory inspection results and the last type inspection; when the national product quality supervision agency proposes a requirement for type inspection. Type inspection shall be carried out according to the items specified in Table 1. 5.2.2 Type
Inspection items, clause
MT 381---1995
Factory inspection
Note: "O\" indicates items to be inspected and "--" indicates items not to be inspected.5.2.3 Sampling method and judgment rules
5.2.3.1 Sampling method
Type inspection
According to the provisions of GB10111, random sampling shall be carried out from products that have passed the factory inspection. The sampling quantity shall not be less than 2 units and the sampling base shall not be less than 5 units.
5.2.3.2 Judgment rules
Inspection items of the inspected samples, 3.2, 3.4.3, If one of the following items is unqualified, or two of the following items are unqualified, the product batch shall be doubled for inspection. If there are still unqualified items, the product batch shall be deemed unqualified.
6 Marking, packaging, transportation, storage
6.1 Marking
6.1.1 Product marking
The sensor housing shall have the "Ex" explosion-proof mark and the "MA" mining safety mark on it. The nameplate of the sensor should be firmly set in a conspicuous position on the casing, and its contents should be as follows: 6.1.1.2
Product model and name;
There is an obvious "Ex" mark in the upper right corner of the nameplate; Explosion-proof type, category, level and temperature group: ibI (+150℃); main technical parameters,
associated equipment model;
Explosion-proof certificate number;
Safety mark number:
Measuring instrument license mark and number:
Product number and publication date;
Manufacturer name.
Packing mark
MT 381--1995
The packing, storage and transportation mark shall comply with the provisions of GB191. The outer wall of the packing box shall have the following marks:
Product model and name:
Name and address of the consignee;
Gross weight and net weight:
Rainproof, handle with care and other marks,
Manufacturer name.
6.2 Packaging
Put the qualified products together with the accessories into plastic bags and packing boxes containing shock-absorbing materials. 6.2.1
The packing box shall have the following documents:
Product certificate;
Product instruction manual:
Packing list.
6.3 Transportation
During transportation, the products shall be protected from direct exposure to rain and snow. 6.4 Storage
The product should be stored in a well-ventilated warehouse with a temperature of -10 to 40°C and no corrosive gas. Additional remarks:
This standard was proposed by the Coal Mine Safety Standardization Technical Committee of the Ministry of Coal Industry. This standard was submitted by the Shelter and Equipment Branch of the Coal Mine Safety Standardization Technical Committee of the Ministry of Coal Industry. This standard was drafted and interpreted by the Chongqing Branch of the China Coal Research Institute. The main authors of this standard are Yan Jiayuan, Jin Decai and Chen Benping. : 224
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