Precision Table-Top Portable Thermal Chamber with Double Thermoelectric Module

A portable thermal chamber with a volume of only 2.5 l capable of reaching temperatures over the −5C to 70C range was designed and constructed. In order to make the thermal chamber lightweight and portable, two series connected thermoelectric modules were used as actuators since their size and performance characteristics allow the portability and precise temperature control. The PID control provided stability and errors better than normally found in expensive commercial thermal chambers, with maximum temperature error of ±0.2C with respect to the setpoint and with a fluctuation of ±0.1C. Key–Words: Thermal chamber, Thermoelectric modules, Stacked Thermoelectric modules, Analogue PID, Temperature control, H-Bridge power driver.