... a laser light source irradiates on the particles; then the solid state detector detects the scattered light; and at last, the optical ... electrical signals. The electrical signals are classified and counted according to the pulse amplitude after amplification, and then been accumulated in ... , 4, 5, 7.5, 10, 15, 20 umCount Range : 1 to 1,000,000 particle/literZero count : < 1 per 5 min ...