804 portable four channelAir fine suspended particle detectorIt is a professional laser principle air suspension particle measurement device with mature technology and excellent stability of measurement results. MetOne 804 integrates complete modules such as vacuum pump, particle counting, microprocessor, storage, etc. It can measure different particle sizes and micrometer sizes according to user needs, including>0.3um,>0.5um,>0.7um,>1.0um,>2.5um,>5.0um, and>0.7um. It can also measure suspended particles of four different sizes simultaneously and display the total number of suspended particles of each size. The measurement unit is particles per cubic foot. The sampling time of ET-804 is very fast, and the operator can customize the sampling time between 6-30 seconds according to different measurement needs.