The NPL radionuclide calibrator—Type 271

Abstract

This paper describes the construction and performance of the new NPL radionuclide calibrator (type 271)†—an instrument designed to provide values of radionuclide activity which are directly traceable to national standards. The instrument is a combination of a re-entrant ionization chamber (model 671) and an electrometer (model 271) which provides a digital display of the radionuclide activity. The radionuclide calibrator is the successor to the type 1383A ionization chamber.