Abstract Thermoluminescence dosimetry has been very successful in monitoring the personnel level doses due to high sensitivity and reusability. However, these dosimeters saturate at high doses involved in radiation processing. Present investigations show that the range of high dose measurements can be increased by an order of magnitude by increasing the concentration of dysprosium in CaSO 4:Dy. A further increase in high dose measurements is possible by considering the ratio of two high temperature peaks. As the ratio of two peaks is an intrinsic property of the material, it is expected that the initial calibration of these dosimeters may not be required. This may be advantageous at very high doses where calibration of the dosimeters is quite problematic. Use of thermoluminescence peaks higher than 300°C also make this technique appropriate for high dose measurements at high temperatures.