The S40 portable particle counting system for on-site use uses an internal direct view piston pump to deliver constant flow rate samples to sensors for both non pressure samples and pressure up to 420 Bard pressurization systems. It is mainly used for measuring solid particle contamination in oil and other liquids. A single particle counting system designed and manufactured based on the principle of light blocking, using specially manufactured sensing cells and selecting precision optical components, can ensure high resolution and accuracy. Each particle detected by the sensor will be counted according to its size. Set up 8 adjustable particle size channels and display the complete number and size of particles.