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1, wind speed
(a) The area of ​​the plane 10 cm downstream of the main filter or diffuser is divided into areas of not less than twelve equal parts, and the center point of each area is the wind speed measuring point. However, the spacing between the measuring points should not exceed 25cm;
(b) Calculate the arithmetic mean value of the cross-section wind speed and the uniformity rate of the wind speed by calculating the wind speed values ​​of the respective measuring points.
2, the number of suspended particles
(a) The concentration of the suction (for particles ≥ 0.5 um) shall not be less than 35,000 granules/L; it is not suitable for the dispersion of aerosols at the suction site;
(b) Test continuously 5 times at the center of the parallel section 250 mm away from the main filter or the rectifying grid outlet, and find the average value. The sampling amount should not be less than 1L.
3, sedimentation bacteria
The j90mm culture dish containing nutrient agar was placed on the operation interface of the workbench, and the measurement was placed on the suspended particles. After exposure for 0.5 h, the lid was placed, and the culture dish was taken out and cultured in an environment of 30 ° C to 35 ° C for 48 hours. The visible bacterial colonies were counted with the naked eye and their arithmetic mean was taken.
4, illumination
The measuring points are arranged on the center line of the horizontal direction of the clean workbench, and three points are evenly arranged, and the arithmetic average is taken as the illumination of the clean workbench.
5, high efficiency filter (PAO) leak detection
The aerosol was sprayed to the upstream side of the high efficiency filter while the aerosol inspection was performed with the aerosol generator at a distance of about 2.5 cm from the high efficiency filter outlet on the downstream side. Scanning speed ≤ 5cm / s. When the ratio of the concentration on the downstream side to the concentration on the upstream side is more than 0.01%, it is considered that there is a significant leak.
6, noise
The noise measuring point of the clean workbench should be placed in the center of the workbench, 20cm away from the front of the platform, and the height is 110cm (equivalent to the position of the ear where the operator sits). The noise measuring points of other local purification equipment shall be arranged at a horizontal distance of 100 cm from the geometric center of the main surface of the equipment and a height of 150 cm. It should be measured once every four sides and take the arithmetic mean of four points.
7, air flow pattern
(a) Vertical airflow test
The smoke is located 150mm inside the front window and moves from one side wall panel to the other side wall panel operating area at a height of 300mm. The vertical descending airflow of the clean working table exhibits a descending mode in the lower part of the current sharing plate without upward airflow.
The smoke is located at a depth of 1/2 of the inner working area of ​​the front window, and moves from one side wall panel to the other side wall panel operating area at a height of 300 mm. The vertical descending airflow of the clean working table exhibits a descending mode in the lower part of the current sharing plate, Upward airflow. The smoke moves 150mm from the rear side wall of the operation area and moves from one side wall to the other side wall operation area at a height of 300mm. The vertical descending airflow of the clean workbench shows a descending mode in the lower part of the flow plate, no upward airflow. .
(b) Horizontal airflow test
The smoke is located at a depth of 1/2 of the inner working area of ​​the front window, and moves from one side wall panel to the other side wall panel operating area at a height of 300 mm. The horizontal airflow of the clean working table exhibits an outward mode on the front side of the diffusing hole. No inward airflow.
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