What are the advantages of the combination of light extinction and light scattering techniques?

The combination of light extinction and light scattering technologies increases measurement accuracy. When a particle passes through the illuminated zone, the laser will be blocked, resulting in attenuation in the direction of light propagation, which will be identified by the extinction detector, and a negative pulse will be formed subsequently on the signal diagram. Simultaneously, the light will be scattered at a certain angle. Therefore, the scattered light signal will be received by the scattering detector, yielding a positive pulse, which corresponds to the negative pulse caused by the same particle on the extinction detector. For the same particle, its positive and negative pulse signals correspond to the same x-coordinate in the signal diagram. Therefore, these two coordinated pulse signals can verify each other, and any other pulses not verified will point to the possibility that the signal is treated as noise.

Light extinction technology enables particle counting and sizing with high resolution down to 1μm. For fine particles smaller than 1μm, laser scattering is more sensitive, so the application of light scattering expands the measurement range.

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