Calibrator for radioactivity well logging tools

摘要

A radioactivity logging tool including a gamma ray detector is field calibrated with the help of a sleeve that has a radioactive material distributed therein and is clamped about the tool so as to completely surround the detector. The radioactive material is peferably uranium 238. It can be either distributed uniformly inside the sleeve or take the form of wires which extend along generatrices or circumferences of the sleeve.