Environmental Monitoring with a Portable TLD System

Two types of TLD systems are used for environmental dose monitoring: One is based on an NHZ-203 laboratory TLD reader and CaSO4:Dy powder. The other is based, on CaSO4:Tm bulbs and a small, portable TLD reader built into a cross-country car and operated by means of the car battery. The laboratory TLD system has been used for many years for environmental monitoring and it has been tested and proved satisfactory at international intercomparisons for environmental dosemeters. The new portable TLD system has the advantage of being able to establish the dose in a few minutes at the environmental station. The transport dose is omitted as the TLDs are evaluated at the field site. The evaluation of a bulb needs only a few minutes, and the measured dose value can be reported back by radio - an important aspect during an emergency situation.