This standard applies to the test of the liquid level indicator (hereinafter referred to as the indicator) used in the liquid tank of the underground coal mine emulsion pump station. MT 92-1984 Test specification for liquid level indicator used in coal mine emulsion pump station MT92-1984 Standard download decompression password: www.bzxz.net

Ministry of Coal Industry of the People's Republic of China Standard for Liquid Level Indicators for Emulsion Pumping Stations in Coal Mines
Test Specifications
MT 92-84
This standard applies to the test of liquid level indicators (hereinafter referred to as indicators) used in conjunction with the liquid tanks of emulsion pumping stations in coal mines. 1 General
Indicator tests are divided into type tests and) tests. 1.1
1.2 Type tests should be carried out in the following cases: a.
When the design, process or material of the product is changed and the product performance is affected; b.
When the superior quality management department makes a request for the production of products that have been discontinued for more than one year or mass-produced products; c.
When the user has major objections to the product quality. 1.3 Before the product is shipped, it should be tested piece by piece. 1.4 The number of type tests is 3 pieces, of which 11 pieces are subjected to continuous action tests. For mass-produced products, if the test results do not meet the requirements of the type test, 6 pieces will be retested, of which 2 pieces will be subjected to continuous action tests. If it still does not meet the requirements, it is unqualified. 1.5 The test unit shall provide complete test pieces and matching pump sets, accumulators and pipeline accessories and connection dimensions related to the test. It shall also provide information such as instruction manual, inspection record, general design drawing, wearing parts drawing, hydraulic system drawing of pump station, etc. 2 Test device and measurement accuracy
2.1 Test device
Use the matching liquid tank of the test indicator. The liquid tank should be equipped with a liquid scale with a scale. The minimum scale should not be greater than 5mm. The lower limit of the liquid scale should not be higher than the lowest indication value of the indicator, and the upper limit should not be lower than the highest indication value of the indicator. 2.2 Instrument accuracy
The instrument accuracy should meet the requirements of the test items. 2.3 Test working fluid
2.3.1 The indicator with emulsion as the working fluid For indicators, use the emulsion prepared by mixing the emulsion oil specified in MT76--83 "Emulsion oil for hydraulic support" with neutral soft water at a weight ratio of 5:95. 2.3.2 For indicators with water as the liquid, use clean water. 3 Test method
Test items
All kinds of tests on indicators should be carried out according to the items in the table. Ministry of Coal Industry of the People's Republic of China Issued on October 16, 1984 120
1985-0101 Implementation
MT 92 --- 84
Test items
Accuracy testbZxz.net
Continuous action test
Switch circuit test
Insulation resistance test
Withstand voltage test
Insulation moisture resistance test
Immunity test
Voltage fluctuation test
Explosion-proof test
Test types
Note: Items 1 and 2 in the table are mechanical indicator test items, and items 3 to 9 are energized indicator test items. √ indicates that the test should be carried out. ||tt ||× means no test.
General requirements
The various tests of the indicator shall be carried out in the order in the table. If the test results of all items meet the requirements, the liquid level indicator is qualified. No replacement of parts is allowed during the entire test process.
3.2.3 The number of measurements of each measurement parameter shall not be less than 3 times, and the arithmetic mean shall be taken as the measurement value. 3.3 Accuracy test
3.3.1 Raise the liquid level to the highest value set by the indicator, and then lower the liquid level to the lowest value of the indicator, repeat 5 times, and record the reading value.
The highest and lowest reading values ​​shall be within the deviation range of ±20mm of the specified highest and lowest liquid level values. 3.3.3 The error when the indicator sends a signal (or indicates) shall be within ±20mm. 3.4 Continuous action test
Repeat the test 20 times according to the method of 3.3.1, and each time shall meet the requirements of 3.3.2 and 3.3.3. 3.5 Switch circuit test
3.5.1 When the switch circuit is powered on for 8 hours and the ambient temperature is 50℃, it can still work normally. 3.5.2 The amplitude is 5mm and the vibration frequency is 25 times/min. It can still work normally after the vibration test. 3.5.3 It can still work normally after the 48h aging test. 3.6 Insulation resistance test
The test shall be carried out in accordance with Article 6.2 of GB998-82 "Basic test methods for low-voltage electrical appliances" and shall comply with relevant regulations. 3.7 Withstand voltage test
MT 9284
The test shall be carried out in accordance with Article 6.3 of GB998--82 and shall comply with relevant regulations. 3.8 Insulation moisture resistance test
The test shall be carried out in accordance with Article 826.4 of GB998--82 and shall comply with relevant regulations. 3.9 Immunity test
The test shall be carried out in accordance with Chapter 12 of GB998-82 and shall comply with relevant regulations. 3.10 Voltage fluctuation test
Test according to the general requirements for electrical equipment in coal mining working faces. When the test voltage is 75-110% of the rated voltage, the indicator should be able to work normally.
3.11 Explosion-proof test
According to the designed explosion-proof type of the indicator, test according to GB3836.1--83 "General requirements for explosion-proof electrical equipment for explosive atmospheres", GB3836.2-83 "Explosion-proof electrical equipment for explosive atmospheres Flameproof electrical equipment "d"", GB3836.3-83 "Explosion-proof electrical equipment for explosive atmospheres Increased safety electrical equipment "e"", GB3836.4-83 "Explosion-proof electrical equipment for explosive atmospheres Intrinsically safe circuits and electrical equipment "i"" and the provisions of the Ministry of Coal on electrical equipment and comply with their provisions. 4 Signal requirements
4.1 When the liquid level reaches the highest or lowest position specified in the design, the indicator light should light up and ring. 4.2 The pump should be stopped when the liquid level reaches the dangerous position specified in the design. 4.3 The indicator light, ringing time and time interval should be adjustable. Additional remarks:
This standard was proposed by the Technology Development Department of the Ministry of Coal Industry. This standard was drafted by the Taiyuan Branch of the Coal Science Research Institute. The main drafter of this standard was Liu Zhongzhang.
This standard is entrusted to the Taiyuan Branch of the Coal Science Research Institute for interpretation. 122
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.