Working Principle of Aerosol photometer

For leakage detection for HEPA Filter, it is well known to use aerosol photometer for testing. Today, We will take ZR-6012 Aerosol Photometer as an example to introduce the detection principle for you.

Aerosol Photometer is designed base on Mie scatter principle, which can effectively detect particles range 0.1 ~ 700 μm. When detecting the leakage of high-efficiency filter, it needs to cooperate with Aerosol Generator. The generator emit aerosol particles with different sizes, and then use the scanning head of photometer to detect the filter. The leakage rate of high-efficiency filter can be detected In this way.
The air flow is pumped to the light scattering chamber, and the particles in the flow are scattered to the photomultiplier tube. The light is converted into an electrical signal in the photomultiplier tube. After amplification and digitization, it is analyzed by the microcomputer to determine the intensity of the scattered light. Through signal comparison, we can obtain the concentration of particulate in the flow. If there is an alarm sound (the leakage rate exceeds 0.01%), it indicates that there is leakage.



When detecting the leakage of high-efficiency filter, we need to cooperate with aerosol generator. It emits aerosol particles with different sizes, and adjusts the aerosol concentration as required to make the upstream concentration reach 10 ~ 20ug / ml. Then the aerosol photometer will detect and display the concentration of the particle mass.


Post time: May-10-2022