Rotameter Calibration

The ball-type flowmeters and rotameters built into most air sampling pumps are primarily intended to serve as flow indicators and have of low accuracy. The easy-to-read scales are ideal for performing routine verifications of air flow easily in the field. The flowmeters or rotameters must be calibrated against a primary standard such as a film flowmeter or electronic calibrator to verify accuracy. Rotameters are recommended for calibration at least once a year.