Radioactive Standards and Methods of Testing Instruments Used in the Measurement of Radioactivity

A summnary of the program for standardization of radioisotopes at the National Bureau of Standards is given in this paper, with some of the reasons for need of absolute measurements of radioisotopes in particular uses. This is accompanied by an outline of some of the methods used to ascertain characteristics of commercial instruments used in the measurement of radioactivity, with particular emphasis on those methods used at the National Bureau of Standads for this purpose.