Sharing of items and standards for clean room testing 1/2

1. Wind speed, air volume, ventilation frequency
The cleanliness of clean rooms and areas is mainly achieved by sending a sufficient amount of clean air to replace the particulate pollutants generated in the dilution room. Therefore, it is very necessary to measure the supply air volume, average wind speed, supply air uniformity, airflow direction, and flow pattern of a clean room or clean facility.
For the completion acceptance of clean room engineering, China's "Clean Room Construction and Acceptance Specification" (JGJ 71-1990) clearly stipulates that testing and adjustment should be carried out in an empty or static state. This regulation can better evaluate the quality of the project in a timely and objective manner, and can also avoid disputes over project closure due to the inability to achieve dynamic progress as scheduled.
In actual completion testing, static state is predominant and empty state is rare. Because some of the process equipment in the clean room must be in place in advance. Before cleanliness testing, the process equipment needs to be carefully wiped to avoid affecting the test data. The regulations in the "Code for Construction and Acceptance of Clean Rooms" (GB50591-2010) implemented on February 1, 2011 are more specific: "16.1.2 The occupation status of clean rooms during inspection is distinguished as follows: engineering adjustment testing should be empty, engineering acceptance inspection and daily routine inspection should be empty or static, and use acceptance inspection and monitoring should be dynamic. When necessary, the inspection status can also be determined through consultation between the construction party (user) and the inspection party
Upflow mainly relies on clean airflow to push and displace polluted air inside the room and area to maintain cleanliness. So the wind speed and uniformity of its air supply section are important parameters that affect cleanliness. The higher and more uniform the cross-sectional wind speed, the faster and more effective the removal of pollutants generated by indoor processes, so they are our main focus on clean room testing projects.
Non unidirectional flow mainly relies on the supplied clean air to dilute and dilute pollutants in the room and area to maintain its cleanliness. The results indicate that the greater the number of air changes, the more reasonable the airflow pattern, and the better the dilution effect. Therefore, the air supply volume and corresponding air change frequency of non single-phase flow clean rooms and clean areas are highly concerned airflow testing projects.
2. Temperature and humidity
The temperature and humidity measurement of clean rooms or clean facilities can generally be divided into two levels: general testing and comprehensive testing. The completion acceptance test in the empty state is more suitable for the next level; Static or dynamic comprehensive performance testing is more suitable for the next level. This test is suitable for occasions with strict requirements for temperature and humidity.
This test is conducted after the airflow uniformity test and the adjustment of the air conditioning system. During this testing period, the air conditioning system operated well and various conditions have stabilized. It is necessary to set up at least one humidity sensor in each humidity control area, and provide sufficient stabilization time for the sensor. The measurement should be suitable for practical use until the sensor stabilizes before starting the measurement, and the measurement time must be greater than 5 minutes.