Air Pollution Measurements by Means of a Beta Gauge

Optical absorption constant of suspended particulate matter. An air pollution index

“…On the other hand, Mackay has pointed out that, for solids, f/fr decreases with increasing melting point (mp) and molecular weight, and a precise relationship between K and S must, therefore, take into account factors such as the melting point, entropy of fusion, and the difference between solid and liquid heat capacities. A step toward this direction has been made by Yalkowsky and Valvani (8, 9), who propose an equation of the type log K = a (log S) + t>(mp) + c…”

“…The counting frequency with unloaded filters is ~3 kHz; thus a counting time of 102-103 s provides a statistical accuracy which is better than 10% (1 ) in most cases. Performances of the instrument are discussed elsewhere (9).…”