Clean room airflow pattern testing specifications

1. The detection of airflow pattern includes visual inspection of airflow and test of airflow direction. Visual inspection of airflow can be carried out by tracer line method, smoke (fog) method and image processing technology. The test of airflow direction generally adopts tracer line method, smoke (fog) method and three-dimensional method to measure airflow velocity.

2. When using the tracer line method, light fibers such as nylon monofilament line, cotton line and film tape can be used, placed at the end of the test rod, or installed on the filament grid in the airflow to directly observe the direction of the airflow and the fluctuation caused by interference.

3. When using the smoke (fog) method, deionized water can be used, and solid carbon dioxide (dry ice) or ultrasonic atomizer can be used to generate water mist with a diameter of 0.5~50μm. When titanium tetrachloride (TiCl4) is used as tracer particles, it should be ensured that the clean room, indoor equipment and operators are not harmed by the acid generated by titanium tetrachloride.

4. When using image processing technology for visual inspection of airflow, the particle image data on the camera or membrane obtained by the above operation provides quantitative airflow characteristics using two-dimensional air flow velocity vectors. Image processing technology requires a digital computer with suitable interfaces and software.

5. The three-dimensional method is used to measure the airflow velocity, and a hot ball anemometer or ultrasonic anemometer is used. The detection points are selected at the key working area and the height of the working surface. When the uniform distribution test of the airflow direction of the clean room (area) is required according to the construction party, multi-point testing should be carried out.