The following three tests should be carried out in a clean room or area:
1) Air cleanliness test (biological cleanroom should be tested for plankton and sedimentation bacteria);
2) Static pressure difference test;
3) Wind speed or wind measurement. In addition, there are some projects that can be negotiated for testing. The test cycle of each test item shall meet the requirements of the following table. [1]
Table 1 Test cycle of clean room or clean area
1. Detection of cleanliness
1) Optical particle counter (OPC) with sampling amount greater than 1L/min should be used in selecting the instrument, taking into account the ability of particle size identification, the applicable range of particle concentration and the counting efficiency. The instrument should have an effective certificate of calibration.
2) The minimum sampling points shall be calculated according to the following formula:
In the formula, NL is the minimum sampling point; A is the area of clean room or clean area.
3) Sampling points should be evenly distributed in the whole area of clean room or clean area, and located at the height of working activities, which should be 0.8m away from the ground; the minimum sampling time of each sampling point is 1 minute.
4) Each sampling point should have at least 2L of sampling volume, which should be calculated according to the following formula:
In the formula, VS is the sampling quantity of each sampling point, L; Cn m is the limit of the measured particle size of the air cleanliness grade of the cleanroom under test, PC /__________.
2. Wind Volume or Speed Testing
1) One-way flow clean room: the air supply volume is determined by means of the average air velocity and cross-section product of the room cross-section. The measuring point is located at the outlet surface of the high-efficiency filter about 150 mm to 300 mm. The cross-section of the vertical air flow is taken as the sampling section. The distance between the measuring points on the cross-section should not be greater than 0.6 m, the measuring points should not be less than 4, and the arithmetic average of all the readings should be taken as the sampling section. Average wind speed.
2) Non-unidirectional flow clean room: The air supply rate can be determined by tuyere or duct method, which can be carried out according to the method stipulated in GB 50243 of the current national standard "Code for Acceptance and Acceptance of Construction Quality of Ventilation and Air Conditioning Engineering".
3. Static pressure difference test
The measurement of static pressure difference should be carried out after passing the test of air speed, air volume and uniformity of air supply in clean room (area), and should be carried out when all doors are closed. Various differential pressure gauges should be used and the sensitivity of the instrument should be less than 1.0Pa.
4. Leak detection test of installed filters
Leak detection methods include photometer method and particle counter method. The aerosol for testing should be introduced on the upper side of the filter. The isodynamic sampling head of the photometer or particle counter should be placed on the lower side of the filter at a distance of 2 cm~3 cm from the surface of the filter to move at a scanning speed of 5 mm/s~15 mm/s. Attention should be paid to the scanning at the installation junction.
5. Closure test
It is used to confirm whether contaminated air seeps into the clean room (area) from the adjacent clean room (area) or non-clean room (area) through the ceiling, partition wall and other surfaces or doors and windows. It is generally suitable for testing in clean rooms (areas) of grade 1 to 5. The photometer method and particle counter method were used to test.
Reference material:
[1] Ministry of Industry and Information Technology of the People's Republic of China. Clean workshop design code GB50073-2013 [S]. Beijing: China Planning Publishing House, 2013.
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