1. The air volume and wind speed detection must be tested first, and the purification air conditioning effects must be obtained under the designed air volume and wind speed conditions.

2. Before the air volume detection, it is necessary to check whether the fan is running normally, whether the components in the system are installed correctly, whether there are obstacles (such as whether the filter is blocked or blocked), all valves should be fixed in a certain open position, and the size of the measured air outlet and air duct must be actually measured.

3. For unidirectional flow (laminar flow) cleanrooms, the air supply volume is determined by multiplying the average wind speed and cross-sectional area of the room section. The measured cross-sectional area of the vertical unidirectional flow (laminar flow) cleanroom is the horizontal cross-sectional area 0.8 m from the ground, and the horizontal unidirectional flow (laminar flow) cleanroom is the vertical cross-sectional area 0.5 m from the air supply surface. The distance between the measuring points on the cross-sectional area should not be greater than 2m, and the number of measuring points should be no less than 10, evenly arranged. The instrument uses a hot ball anemometer.
 

4. For turbulent cleanrooms, the air outlet method or air duct method is used to determine the air supply volume. The methods are shown in Item 6, Item 7 and Item 8 respectively. 5. For air outlets without filters, the method in Appendix 1 of the current national standard "Construction and Acceptance Specifications for Ventilation and Air Conditioning Engineering" GBJ243 can be used.

6. For air outlets equipped with filters, auxiliary air ducts can be selected according to the form of the air outlet, that is, a straight pipe section with the same surface as the air outlet and a length equal to twice the side length of the air outlet can be made of hard plate, connected to the outside of the filter air outlet, and the measuring points are evenly arranged at least 6 points on the outlet plane of the auxiliary air duct, and the wind speed at each point is measured with a hot ball anemometer. The air volume is determined by the net cross-sectional area of the average wind speed of the air outlet section.

7. For air outlets equipped with similar diffusers, the air volume can be found out based on the diffuser air volume resistance curve (factory air volume resistance curve or on-site measured air volume resistance curve) and the measured diffuser resistance (the difference between the pressure inside the orifice plate and the indoor pressure). When measuring, use a micromanometer and a fine pitot tube, or use a fine rubber instead of the pitot tube, but the measuring hole plane must be parallel to the airflow direction. In addition, other methods approved by professional testing departments may also be used.

8. When there is a long branch pipe section on the upwind side of the air outlet and holes have been or can be drilled, the air duct method can be used to determine the air volume. The distance between the measuring section and the local resistance component shall not be less than 3 times the pipe diameter or 3 times the length of the large side in the former part of the local resistance component, and not less than 5 times the pipe diameter or 5 times the length of the large side in the latter part of the local resistance component.

9. For rectangular air ducts, divide the measuring section into several equal small sections. Each small section is as close to a square as possible, and the side length should not exceed 200mm. The measuring point is set at the center of the small section, but the number of measuring points on the entire section should not be less than 3. For circular air ducts, the measuring section and the number of measuring points should be determined according to the equal area ring method.