The field air flow calibrator is ideal for field calibration of PM2.5 Sampler. It works with a precise flow of 16.67LPM and calibrate air flow ranging from 1-30 LPM. The calibrator is available with measuring provision for barometric pressure and ambient temperature and NIST trace ability. It is suitable for temperature range of -30° to +55° C and displays both actual and standard flow rates. The device is and is powered by battery. It is simple in operation with no moving parts. The flow through the instrument is uninterrupted and the graphic software provides a continuous output display for all the functions.