Recent developments and performance of survey instruments for the monitoring of weakly penetrating radiations

Dose rate monitoring for weakly penetrating radiation is often attempted by modifying conventionally designed survey meters. Evaluation of such instruments has shown they are not accurate for such monitoring and has helped identify the requirements for such monitoring, but few commercially available instruments utilise this knowledge. Survey instruments that have internal corrections for source geometry and spectrometers that separate beta radiation from photon radiation using coincidence techniques have been developed and are described. Contamination monitoring for some nuclides also involves monitoring of weakly penetrating radiation. Such monitoring requires the use of special counters and specialised techniques. (author)