A New Type of Spurious Reading in TL Personnel Montioring

A particularly serious type of reading in automated TL personnel monitoring has been observed. These readings simulate dose values up to several mSv and con only be detected by flow curve analysis. Characteristic for these events are high artificial dose values and irregular glow curves of a particular shape. Extensive investigations to reproduce this effecht purposely faild to produce any results. It can be assumed, however, that it must be some chemical surface contamination, wich penetrates the saled dosemter bag or which is transferred from the bag to the detector. The effect can bee eliminated by manual cleaning of the dosemeter cards. The importance of this observation lies in the fact that only proper low curve evaluation can prevent the monitoring service from reporting artificial high dose readings creating lots of serious problems. The paper shows how this problem can be avoided for the kind of spurious effect, if glow curves are available and stored for every dosemeter readout.