Description

Vathi Instruments PM*0 and PM2.5 Monitor VDPM ***0, Real Time Portable Beta Attenuation Mass Monitor, continuously measures the mass concentration of ambient particulate matter collected onto glass filter tape with time resolu-tion of one-minute. The PM*0 and PM2.5 Monitor VDPM****0 employs an in-line sampling geometry in which the attenuation of beta rays across filter media is measured and particulate matter is sampled simultaneously. This allows ambient sampling to occur for virtually *0 minutes each hour. It also allows for beta ray measurements to be made for virtually the entire hour thereby improving sensitivity and time resolution. VDPM ***0 employs a unique in-situ sampling technique where the beta measurement is kept at a near fixed temperature above ambient conditions, thereby minimizing measurement error due to loss of semi-volatile particulate material or due to excessive moisture in the sample stream. Highly accurate measurements are made without having to employ expensive Nafion dryers thereby increasing reliability and decreasing operating costs.