The aerosol concentration detection photometer can indeed be used to detect whether there is leakage in high-efficiency filters. Its principle, operation method, application scenarios, and advantages are as follows:

1、 Working principle

The aerosol concentration detection photometer is based on the Mie scattering principle, which calculates the concentration of aerosols by measuring the intensity of scattered light generated when light passes through aerosol particles. In efficient filter leak detection, it achieves leak detection through the following steps:

1. Aerosol generation: Use an aerosol generator (such as a PAO/DOP generator) to generate a stable concentration of aerosols upstream of the high-efficiency filter as a dust source.

2. Upstream concentration setting: After the aerosol is uniformly mixed and the upstream concentration is stable, use a photometer to detect and set the upstream concentration as the 100% reference value.

3. Downstream scanning detection: Use a photometer sampling head to scan point by point downstream of the high-efficiency filter to detect aerosol concentration.

4. Leakage rate calculation: The ratio of downstream concentration to upstream concentration is the leakage rate (also known as transmittance) of the high-efficiency filter.

2、 Operation method of aerosol concentration detection photometer

1. Determine the upstream concentration sampling port: usually located near the upstream end of the high-efficiency filter, connected by a hose to a location that is easy to sample.

2. Determine the location of dust emission: Choose to emit dust at the negative pressure end of the fan to ensure that aerosols can be fully mixed and sucked into the system by the fan. If the conditions are not met, dust should also be generated near the high-efficiency filter, but the airflow pressure must be overcome.

3. Adjust aerosol concentration: Connect an inert gas source to the aerosol generator, adjust the gas pressure to make the aerosol generator generate dust, and test the aerosol concentration at the upstream concentration testing port. When the upstream concentration stabilizes, set this concentration as the 100% reference concentration. The variation of upstream concentration over time should not exceed ± 15% of the average measured value

4. Scanning test: Use the sampling head of a photometer to scan the entire working surface of the high-efficiency filter (including the filter medium, filter frame, between the filter frame and the static pressure box, and the static pressure box itself). When scanning, the distance between the sampling head and the filter is less than 5cm, and the speed is less than 5cm/s. Scanning should be repeated back and forth, and the lines should overlap.

3、 Application scenarios

Aerosol concentration detection photometers are widely used in industries that require high cleanliness environments, such as food and drug production, electronic manufacturing, biological laboratories, etc. In these scenarios, leak detection of efficient filters is crucial to ensure the cleanliness of the production environment and product quality.