A scanning integrating histophotometer

Abstract

A scanning integrating microdensitometer for use in cytological determinations is described. The object to be measured is directly and uniformly scanned by a mechanically driven series of holes drilled in a metal disk. The measurement is made by comparison between a test and a reference photomultiplier. The degree of independence from the various sources of error is such as to give the apparatus a high degree of precision and sensitivity.