Particle analyzer PM2

PEMSemissionsportable

The SEMTECH® PM2 is a 2nd generation on-board Particulate Mass measurement device that combines real-time and cumulative PM measurements. The real-time PM mass measurement is based on an ion mobility technique, and the cumulative PM mass measurement is based on the gravimetric method using industry standard 47 mm filter cartridges. The system is compatible with the SEMTECH® DS+ portable emissions measurement system (PEMS). The PM2 analyzer utilizes an ejector dilution system. HEPA filtered dilution air flows into the diluter and is directed around the ejector nozzle at a high velocity. This causes a pressure drop which draws in the sample through the nozzle. The raw sample mixes with the dilution air resulting in a stable homogeneous diluted sample. For real-time PM mass measurement, a small fraction of the homogenous diluted sample is passed through a Pegasor PPS-M electrical aerosol transducer, in which particulate matter is charged. As the charged particles exit the detection zone, their charge is measured with a sensitive electrometer. The electrometer signal is then converted to real-time PM mass concentration using a transfer function. For cumulative PM mass measurement, the homogeneous diluted sample is directed through one of three filters. The pre- and post- filter weights provide cumulative PM mass, which is used to scale the real-time mass concentration and obtain accurate, time resolved PM mass measurement. Features Ejector dilution system Traceable reference pressure and flow sensors