[A twin type heat flow microcalorimeter for radioactivity measurement].

A microcalorimeter is described which was developed and tested for measuring the activity of pure beta particle emitters. Two identically made calorimeter cells are used, each 46.5 mm i.

Preparation of tritium standard gas by the use of tritiated methane.

Tritium standard gas for calibrating radioactivity detectors was prepared by the use of tritiated methane synthesized by the reaction of tritiated water with aluminum carbide at ca. 470 degrees C. A long-path proportional counter was used to standardize the radioactivity of the prepared gas.