A new sensitive chemical actinometer. I. Some trials with potassium ferrioxalate

Abstract
A chemical actinometer has been devised whose high sensitivity and precision depends upon the spectrophotometric determination of the photolysis products of potassium ferrioxalate with 1: 10 phenanthroline. The sensitivity is some hundreds of times greater than that of the uranyl oxalate actinometer. The behaviour of the actinometer has been investigated in detail at 3650 to 3663 angstrom, and tests also show that it is suitable for use over a wide range of wave-lengths. The approximate quantum efficiency has been determined at twelve wave-lengths between 4900 and 2537 angstrom. The advantages and possible applications of the actinometer in the measurement of small doses of radiation are discussed.