Install a new filter in the filter holder and energize the sampler. Filters used for flow rate audits should not be used for sampling.

Adjust motor flow control to its operational set point for routine sampling. This set point should correspond to the calculated set point (Isp) determined by the sampler's calibration relationship for the actual ambient conditions.

Allow the sampler to warm up for a minimum of 2 minutes while maintaining the proper rotameter set point.

Adjust manometer or Magnehelic® gage to read zero and connect to pressure tap on MiniFlo transfer standard.

Note: a Magnehelic® gage is sensitive to the position it is in when zeroed (vertical or horizontal). Maintain this position when taking flow readings.

Install the MiniFlo transfer standard on the inlet tube and allow to equilibrate for a minimum of 2 minutes.

Record the transfer standard pressure drop,(H) in inches of water, the ambient temperature (Tact) in degrees centigrade, ambient barometric pressure (Pact) in millimeters of mercury, and the rotameter indicated flow rate, (Qind) in liters per minute.