Detection of air temperature and relative humidity in clean room
1. According to the fluctuation range of temperature and relative humidity, the corresponding instrument with sufficient accuracy shall be selected for measurement. The time interval of each measurement shall not be more than 30min.
2. Clean room measurement layout:
3. Return to the air outlet;
4. Representative locations of constant temperature working area (such as along the surrounding of process equipment or equidistant layout);
5. Clean room center without constant temperature requirements;
6. Generally, the measuring points shall be arranged at the same height which is more than 0.5m away from the external wall surface and 0.8m away from the ground; they can also be arranged on several planes with different heights from the ground according to the size of constant temperature zone.
6.1 the number of measuring points shall meet the requirements of the table.
6.2 clean room with constant temperature and humidity requirements. The fluctuation range of room temperature is arranged into cumulative statistical curve according to the maximum value of deviation control point temperature in each temperature of each measuring point and the percentage of the total number of measuring points. If the deviation value of more than 90% of the measuring points is within the range of room temperature fluctuation, it is in accordance with the design requirements. Otherwise, it is unqualified.
The clean room area temperature is based on the lowest one-time test temperature of each test point. The average temperature of each test point and the number of over deviation points, as a percentage of the total number of test points, are sorted into a cumulative statistical curve. The deviation value of more than 90% of the test points is the area temperature difference, which should meet the design requirements. The relative temperature fluctuation range can be in accordance with the provisions of the room temperature fluctuation range.