Abstract:Calorimetry is an alternative for thermal power characterization of radionuclide decay. Calorimetric system working at thermal equilibrium mode is sensitive to environmental fluctuations during the measurement process and its measurement accuracy is easily effected by environmental temperature fluctuations. As a result, high stability of environmental temperature is required by calorimetry. In order to provide a stable constant temperature environment for the calorimetric system, a temperature measurement and control system based on LabWindows/CVI virtual instrument development platform was designed and developed. The system employed thermoelectric cooler as refrigeration element, Pt100 platinum resistance temperature sensor as temperature measurement element, high-precision digital source meter as power supply, high-precision digital multifunction meter as temperature measurement instrument, network communication, and a Proportion-Integration-Differentiation algorithm which is referred as PID algorithm as control strategy. The completed software realized functions of instruments communication, data acquisition and display, temperature control, data analysis and storage. A temperature control performance test was performed on thermostatic layer of aluminum ingots in calorimetric system for 48 hours which is far longer than time required for single calorimetric test. Result shows that the temperature control system is able to achieve a temperature control accuracy of ±0.2°C, which meets environment stability requirement for the calorimetric system.
