A beta-gauge method applied to aerosol samples

An instrument developed for the routine measurement of aerosol mass using the beta-particle attenuation method is described and evaluated. Factors affecting the precision and the accuracy of the measurement are discussed in detail. Results of intercomparison studies between the beta-gage method and conventional gravimetric methods are presented. The design of the present instrument is particularly well suited for the automatic mass measurements of membrane filters used in modern dichotomous samplers. The precision of such measurements has been shown to be less than + or - 5 microg/sq cm for counting intervals of 1 min per sample.