Abstract: A thermal anemometer is employed to detect the velocity of the air flowing through a personal air sampling device. A microprocessor system is employed to periodically read the signal from the thermal anemometer and calculate the sample air flow rate. The measured flow rate is integrated over the sample period to provide an indication of the total volume of air sampled. Flow rates need not be calibrated during the sample period to insure accurate collection data, thus providing an automated and accurate means for measuring air quality.