This extremely popular, outdoor rated continuous duty air sampling system is intended for secure outdoor ambient particulate and/or gaseous air sampling. The pump, control valve, and control panel are all hard mounted in a heavy gauge TIG welded aluminum, fully lockable, fan cooled, weather proof enclosure. The control panel houses the power switch, fuse protection, resettable electronic timer and either an analog or digital flow display. The telescoping sampling inlets are adjust-able in height to allow for breathing zone air sampling. HI-Q’s MCV-260 mechanical flow control valve maintains a constant flow ±5% of the operator pre-set flow rate (up to the maximum capacity of the pump).