This standard specifies the structure, volume, technical requirements, test methods, inspection rules, marking, packaging and storage of accordion-shaped negative pressure samplers for gas detection tubes. This standard applies to accordion-shaped negative pressure samplers for gas detection tubes (hereinafter referred to as samplers) used in conjunction with longer gas detection tubes. MT/T 630-1996 Technical conditions for accordion-shaped negative pressure samplers for gas detection tubes MT/T630-1996 Standard download decompression password: www.bzxz.net

MT/T 630—1996
Gas detection tubes used to detect certain gases in the air must be injected into the detection tubes with a matching gas sampler. According to the appearance of the gas sampler, there are two types: round and bellows. According to the way of injecting gas into the gas detection tube, there are the so-called "push-in", "vacuum" and "suction" methods. In order to standardize its name, prevent confusion, and be consistent with the gas injection method required by the detection tube, this standard names all the methods of injecting the measured gas into the gas detection tube at a pressure higher than the atmosphere as "positive pressure", and all the methods of injecting the measured gas into the gas detection tube at a pressure lower than the atmosphere as "negative pressure". This standard is proposed by the Science and Technology Education Department of the Ministry of Coal Industry. This standard is under the jurisdiction of the Coal Mine Safety Standardization Technical Committee. The drafting unit of this standard: Fushun Branch of the China Coal Research Institute. The main drafter of this standard: Yang Wenzheng.
This standard is entrusted to Fushun Branch of the China Coal Research Institute for interpretation. 388
Coal Industry Standard of the People's Republic of China
Technical Conditions for Accordion-shaped Negative Pressure Samplers for Gas Detection Tubes
MT/T630-
—1996
This standard specifies the structure, volume, technical requirements, test methods, inspection rules, marking, packaging and storage of accordion-shaped negative pressure samplers for gas detection tubes.
This standard applies to accordion-shaped negative pressure samplers for gas detection tubes (hereinafter referred to as samplers) used in conjunction with longer gas detection tubes.
2 Cited Standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards will be revised, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB7230 Gas detection tube device
GB/T10111 Method of random sampling using random numbers 3 Structure, volume
3.1 The structure of the sampler is shown in Figure 1.
1 Limiting chain, 2 Exhaust valve; 3-- bellows; 4- filter; 5- Detection tube insertion port Figure 1 Schematic diagram of bellows suction sampler
First, squeeze and press the gas in the bellows cavity with your hands, and then use the elastic force of the spring to restore the bellows cavity to its original state, while creating a negative pressure inside it. Approved by the Ministry of Coal Industry of the People's Republic of China on December 30, 1996, and implemented on November 1, 1997
Then the gas sample to be measured is sucked in through the detection tube. MT/T 630—1996
3.2 The nominal volume of the sampler is 50mL (100mL) 4 Technical requirements
4.1 The sampler shall comply with the requirements of this standard and be manufactured according to the drawings and technical documents approved by the prescribed procedures. 4.2 General requirements:
4.2.1 The surface of the rubber and coating parts of the sampler shall be smooth and shall not have obvious defects such as bubbles, delamination and scratches. 4.2.2 The components of the sampler shall not be loose. 4.2.3 The limiting chain of the sampler shall be tightened when the sampler absorbs the specified gas capacity and shall not be loose. 4.3 Performance requirements:
4.3.1 The relative error of the sampler volume shall not be greater than ±5% of the nominal volume. 4.3.2 The gas leakage of the sampler per minute shall not be greater than 3% of its measured volume. 4.3.3 After the durability test, the performance of the sampler shall still meet the requirements of 4.3.1 and 4.3.2. 4.3.4 The operating temperature range of the sampler is 5~40℃. After the temperature test, its performance shall still meet the requirements of 4.3.1 and 4.3.2. 5 Test method
5.1 The test environment temperature is 15~30℃; the atmospheric pressure is 86~106kPa. 5.2 General inspection is carried out with sensory organs and during operation. 5.3 Performance test.
5.3.1 Volume measurement:
Insert a glass capillary with an inner diameter of 0.4~0.5mm and a length of 100~120mm tightly into the detection tube insertion port of the sampler, and the other end of the glass capillary is connected to the upper outlet of the soap film flowmeter with a capacity of 55mL (or 110mL) and a minimum scale of 0.2mL (as shown in Figure 2). At the beginning of the test, stabilize the soap film at the "0" position on the scale, then hold and press the sampler to inhale, and the soap film will rise. When the inhalation is completed and the soap film stops moving, the value indicated is the measured volume of the sampler. Repeat this process three times and take the arithmetic mean, which is the measured volume of the sampler. The relative error (X,%) with the nominal volume is calculated according to formula (1). X,% =
Where: Vo -
Nominal volume of the sampler, mL;
Measured volume of the sampler, mL.
V.× 100
—zero position; 2—scale; 3—glass capillary; 4 sampler; 5 liquid Figure 2 Schematic diagram of sampler volume measurement
5.3.2 Leakage measurement:
MT/T630-1996
Insert a test tube with both ends opened at the test tube inlet of the sampler, and connect the other end of the test tube to the upper outlet of the soap film flowmeter described in 5.3.1. Perform the suction operation according to the method described in 5.3.1 and start the time. After the specified time is reached, record the scale value indicated when the soap film stops moving, which is the volume of gas entering the sampler. Repeat 3 times and take the arithmetic mean, which is the volume of gas passing through the test tube. The percentage (X.%) of the sampler's gas volume per minute to the sampler's measured volume is calculated according to formula (2). X2% = (V- V) × 60 /
Where: V—the volume of gas passing through the gas detection tube, mL—the specified measurement time, S.
5.3.3 Durability test:
Insert a detection tube with both ends opened in the detection tube inlet of the sampler, repeat the suction and exhaust operations 100 times, and then measure the volume and leakage according to methods 5.3.1 and 5.3.2. 5.3.4 Temperature test:
Put the sampler in an environment of 5℃ and 40℃ for 8 hours respectively, take it out and restore it to room temperature, and then measure the volume and leakage according to methods 5.3.1 and 5.3.2.
5.4 Measurement data processing:
5.4.1 When measuring the volume and leakage of the sampler, retain the significant figures to 1 times the decimal point. 5.4.2 When calculating the relative error of the sampler volume and the leakage per minute, calculate to 2 decimal places, rounded to 1 decimal place. 6 Inspection rules
The inspection of samplers is divided into factory inspection and type inspection. 6.1 Factory inspection
6.1.1 The sampler shall be inspected by the factory quality inspection department. It can only be shipped after passing the inspection and issuing a certificate of conformity. 6.1.2 Factory inspection items include 4.2 and 4.3.1, 4.3.2. 6.2 Type inspection
6.2.1 Type inspection shall be carried out in any of the following situations: - When a 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, which may affect the performance of the sampler; - During normal production, an inspection shall be carried out every two years; - When production is resumed after a year of suspension
- When the factory inspection results are significantly different from the last type inspection, the national quality supervision agency proposes a type inspection requirement. 6.2.2 Type inspection items include 4.2 and 4.3.6.3 Sampling
6.3.1 Factory inspection samplingWww.bzxZ.net
Three units (pieces) shall be sampled from the assembled products according to the method specified in GB/T101116.3.2 Type inspection sampling
Three units (pieces) shall be sampled from the products that have passed the factory inspection according to the method specified in GB/T10111.6.4 Judgment rules
When the type inspection is conducted, if two of the seven items in 4.2 and 4.3 are unqualified, the product shall be judged as unqualified; if one item is unqualified, double sampling shall be conducted to re-inspect the unqualified items. If one item is still unqualified, the product shall be judged as unqualified. 7 Marking, packaging, storage
7.1 Marking
7.1.1 Product marking:
The marking on each sampler (piece) shall include: - Product name, model;
Nominal volume;
Manufacturer name, factory number;
—1996
MT/T630
Factory inspection certificate number, inspection date, inspector code. 7.1.2 Product packaging sleeve marking:
The marking on each sampler (piece) packaging sleeve shall include: - Product name, model, nominal volume, number; - Manufacturer name:
- Measuring instrument mark and manufacturing license number. 7.1.3 Packaging box markings:
The markings on the sampler's factory packaging carton should include: product name, model, nominal volume,
quantity;
gross weight, kg;
volume (length × width × height), mm;
name and address of the manufacturer;
date of manufacture;
words and marks such as "handle with care" and "afraid of moisture". 7.2 Packaging
7.2.1 Each sampler (piece) should be packed in a leather or artificial leather case. In addition to the sampler, the case should also contain an instruction manual for use with the test tube and necessary spare parts. 7.2.2 The samplers packed in the case should be packed in a cardboard box according to a certain number and fixed with soft objects without shaking. 7.3 Storage
The sampler should be stored in a dry room at room temperature. 392
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