The purpose of the test is to measure the pressure differences between different pressure zones. Measurements are performed between clean rooms, filters or on separate devices, usually isolators. The test is performed in accordance with the recommendations from ISO 14644-3.
There are clean areas with a positive or negative pressure difference. For systems with a positive pressure difference, the pressure cascade ensures that air moves from cleaner areas to less clean areas. Such systems are used when clean working conditions are required and products do not pose any danger to people and the environment. For systems with a negative pressure difference, the pressure cascade between spaces ensures safe working conditions and protects the environment against hazardous products. In that case the main production area has the biggest negative pressure difference in regard to the environment. All other adjacent areas allow a safe exit.
By measuring the pressure difference, we also detect if the filters are clogged. Connect the instrument to dedicated connections on the clean and dirty side of the filter. When the limit value is exceeded, a filter change is required.
Like clean rooms, there are also isolators with a positive or negative pressure difference in relation to the area where they are located. Constant monitoring of the pressure difference is usual in such systems, but also a periodic check with a calibrated instrument is mandatory.
Measurements are performed using professional digital pressure difference measuring devices of renowned manufacturers: Testo and TSI. All equipment is calibrated annually in an accredited laboratory.