German
French
Italian
Portuguese
Japanese
Korrean
Russian
Does the ultra-clean workbench need to be certified?
Does the ultra-clean workbench need to be certified?The ultra-clean workbench calibration procedure is an important piece of equipment used for clean local work during microbial testing. It has three levels of air filtration: primary, intermediate, and high. Conduct safety assessment for use in ultra-clean workbench. If the experimental materials will cause environmental pollution to the surrounding environment, use in models without exhaust filter plates should be avoided because of the flowing air.The quality control capabilities of the ultra-clean workbench are very limited and only stay at the factory inspection stage, and no relevant calibration procedures have been issued yet. It is very necessary to include the ultra-clean workbench to inspect the measuring instruments and perform periodic verification on them. The correct calibration method for ultra-clean workbench: Clean workbench is widely used in medical and health, pharmaceutical, cosmetics, food, and other industries, and these industries are closely related to human health. If there is a problem with the ultra-clean workbench, it will directly affect the product quality of these companies and pose a direct hazard to the health of users. Our country's quality control capabilities for ultra-clean workbenches are very limited. They only stay at the factory inspection stage and have not yet issued relevant calibration regulations. I think it is very necessary to include the ultra-clean workbench in the inspection of measuring instruments and perform periodic verification on them. Most of the clean workbenches used are Class 100 vertical flow clean workbenches, which are mainly divided into two categories, one is horizontal laminar flow clean workbench, and the other is vertical laminar flow. The following is a summary of my experience in the calibration of a clean workbench for reference during calibration. Biological safety cabinets can also be implemented accordingly. 1. Technical indicators (l) Leak detection. After installation, the ultra-clean workbench must undergo aerosol leakage inspection and seismic inspection. If the concentration on the downstream side of the gap exceeds 0.01% of the concentration on the upstream side, it is considered to have obvious leakage. (2) Cleanliness of the operating area, cleanliness) 0.5 m, the particles must be 3.5 particles/l and more than 5 m particles are not allowed. (3) Wind speed, the average wind speed in the operating area should be within the range of 0.3 to 0.6m/s. Each measuring point should be within ±20% of the average wind speed. (4) Noise, the noise shall not exceed 65db (a sound level). (5) Vibration, the amplitude of the three axial directions (2, y, :) of the operating table shall not exceed 5 m. (6) Lighting, the average illumination of the operating table shall not be less than 300lx. The light should be even and soft to avoid glare. 2. Calibration method Leak detection method: Using a polydisperse dop aerosol, the generator emits dop aerosol to the upstream side of the high-efficiency air filter, and at the same time, the sampler of the leak detection device is used to perform scanning and inspection on the downstream side about 2. sem away from the outlet of the high-efficiency air filter. The sampling is 47.2x one. -5m3/s 28.3l/min", inspection speed sem/s. When the ratio of the concentration on the downstream side to the concentration on the upstream side is greater than 0.01%, it is considered that there is an obvious leak and the leak should be plugged. Cleanliness verification method of operating area: Try to use a dust particle counter with a large flow rate (47.2x10’5m3/s and 28.3l/min). A dust particle counter with a small flow rate can also be used, but the sampling volume must not be less than il. When the aerosol concentration in the operating area reaches a stable condition, test 5 times continuously at the center of a parallel section 250mm away from the main filter or rectifier grille outlet (25mm from the center of the vertical laminar flow ultra-clean work surface), and find the average value. Cleanliness shall comply with the requirements of Section 1(2). Wind speed calibration method: Use a portable hot bulb electric anemometer or a portable thermistor constant temperature anemometer for testing. The area of the plane located cm downstream of the main filter or diffuser plate is divided into no less than twelve equal areas, and the center point of each area is the wind speed measurement point (see Figure 1). The distance between each measuring point should not be greater than 25cm. The arithmetic mean value of the cross-sectional wind is calculated from the wind speed value at each measuring point. Wind speed and wind speed uniformity shall comply with the requirements of Section 1(3). Noise calibration method: The noise test point of the ultra-clean workbench should be arranged in the center of the workbench, 20cm away from the front edge of the workbench, with a height of 110cm, which is equivalent to the position of the operator's ears while sitting. There should be no other reflecting objects within the range of lm near the sound level meter. Noise shall comply with the requirements of Section 1(4). Vibration calibration method: Use a vibration analyzer with a vibration frequency of zhz to 500hz, and a displacement of 0.1 m to 1. SMM, and an acceleration of 0.019 to 109. When the ultra-clean workbench is under normal operating conditions, place the vibration pickup of the vibration analyzer at the geometric center of the operating surface and measure the total amplitude values in the three axes of x, y, and z. The amplitude values in the three axial directions shall comply with the requirements of Section 1 (5). Lighting calibration method: The measuring points are arranged on the transverse center line of the ultra-clean workbench. Three points are evenly arranged and measured with an illuminance meter. The arithmetic average is taken as the illumination of the ultra-clean workbench. The illumination shall meet the requirements of Section 1(6). 3. Precautions (1) The dust particle counter must undergo self-cleaning before measurement, and the first two measurement results are not used because the dust particle counter requires a balancing process. (2) When multiple 5 bym particles appear during testing, multiple sampling should be performed. Only when multiple particles appear, the test value is considered reliable. (3) When measuring noise, if there are baffles at the opening of the equipment operating area, they should all be opened. Special attention should be paid to avoiding the impact of wind pressure, electromagnetic fields, vibrations, etc. generated by airflow on the measurement. (4) When measuring vibration, the clean workbench to be tested should be placed on the ground with relatively small vibration. The influence of the surrounding environment should be avoided during the test. |
