Abstract: The invention provides a radon daughter dosemeter made up of a cyclone, a filter in a filter holder and a radiation detector spaced from the filter. The filter is arranged to filter dust and aerosol particles from air issuing from the air outlet of the cyclone, and the detector is arranged to detect radiation from dust and aerosol particles on the filter. The invention also provides a method of monitoring radiation exposure of persons; and an electrochemical etching cell for the etching of detectors used in the dosemeter.

Abstract: The invention provides a method and apparatus for determining the concentration of an element such as a heavy metal in a matrix of a material such as rock by the X-ray or gamma-ray fluorescence technique.It allows the use of this technique where a sample to be analyzed has a rough or jagged surface. The effect of the rough surface is eliminated by adjusting the distance between the source and/or detector from the sample so that the rate of detection of radiation in a reference energy band is maintained constant for all samples, including reference samples used for calibration. The reference band is at least partly outside the band or bands characteristic of the element sought.