Fiber Density. In the article “Comparison of Fiber Counting by TV Screen and Eyepieces of Phase Contrast Microscopy” (American Industrial Hygiene Association Journal, Vol. 63, pp. 756–761), I. Moa et al. reported on determining fiber density by two different methods. Twenty samples of varying fiber density were each counted by 10 viewers by means of an eyepiece method and a televisionscreen method to determine the relationship between the counts done by each method. The results, in fibers per square millimeter, are presented on the WeissStats site.

Extending the Concepts and Skills