Dust particles are used to detect whether there is a leak in the efficient filter to avoid efficient air filter leakage and affect the entire production. Mainly to detect whether the suspended particles at all points beyond the scope of the clean area requirements, if there is a leak phenomenon, need to plug or replace. This is also relatively simple and accurate method of operation. After installation or replacement of the high-efficiency filter, the installation of the filter must be leaked to ensure that the cleanliness of the clean room meets the requirements.

The main application of the principle of light scattering, counting the use of photomultiplier tube to accept the dust particles to reflect the light to determine the size and quantity, and to analyze the cumulative and digital display. Temperature requirements before the test in the 18-26 ℃; relative humidity control in the 45-65%. Indoor testers should not be more than 2 people. For the room with different cleanliness of the room, the static pressure difference ≥ 5Pa, clean area and non-clean area of static pressure difference ≥ 10Pa; on the process of large dust production room and other rooms should be relatively negative pressure. With these objective conditions, it is necessary to carry out the actual steps:

1. The dust particles counter with water for injection and 75% alcohol wipe and then sterilized by ultraviolet light for 30 minutes into the clean area

2. Place the dust particle counter on the table horizontally. Measure the plastic pipe port to the plug on the filter.

3. Turn on the power. After the instrument is self-checked, the optional plastic tube is removed from the rear panel. The port is placed in the location where it needs to be measured.

4. Detection of the sampling head from the high efficiency filter 2-4cm, along the high efficiency filter inside the border and slow scan, each high efficiency filter at least 5 points to observe the display data. When the inspection period of 3-5cm / s, 0.5um particles> 20, indicating that the amount of leakage exceeded, need to repair or replacement.

After the test, the sampling plastic pipe port to the dust particle counter on the rear panel for self-test. Then turn off the power. Determination of High Efficiency Filter Results of 100 Clean Area by Dust Particle Counter. Through the above determination can we see whether the high efficiency filter leak phenomenon. Whether the need for plugging or replacement, filter repair or replacement must be re-tested.

The recommended maximum time interval is 24 months. DOP leak detection should be performed after installation or replacement of HEPA. When the environmental monitoring shows that the air quality deteriorates, or when the sterility test of the product fails, the culture simulating the filling test fails, it can be leaked as part of the deviation survey. The filter to be tested for leak detection also includes the drying tunnel and Dry oven used by HEPA.