It is well known that environmental gamma-radiation dosimetry is based mainly on thermoluminescent (TL) dosimetry. This method offers considerable advantages, chiefly its high precision, low cost, and wide range. At the same time, its application involves uncertainty because of the need to transport the collected dose from the point of annealing to the place of exposure, and back to the place of evaluation. Should an accident occur, the readout is delayed because of the need to transport the dosimeter to a laboratory equipped with a thermoluminescent dosimeter (TLD) reader. A portable reader capable of reading out the TLD at the place of exposure tan in situ TLD reader) eliminates the above-mentioned disadvantages. The bulb dosimeter system consists of dosimeters and a microprocessor-based portable TLD reader developed by the Atomic Energy Research Institute of Hungary. The latest system consists of a set of CaSO4:Dy TL bulb dosimeters with built-in memory chips, as well as a microprocessor based reader. The measuring range of the system is from 10 mu Gy to 1 Gy (optionally, 30 mu Gy to 10Gy) The microprocessor-based reader's main characteristics are presented in the paper. One of its main features is the removable memory card that can store up to 4000 measured blocks of data (dose, identification number, date and time, and digital glow curve). The mass of the battery operated version of the reader is about 2 kg, and its dimensions are 190 x 155 x 70 mm. The rechargeable battery (9.6 V) provides capacity for about 200 readouts. The reader also works from a 12-V or 24-V car battery. The system was originally developed for and applied to space dosimetry [1-4].
