Refrigerated Thermostatic Bath and Heating Circulator is a PID controlled bath and circulator with a pump flow of 0 ~ 20 L / min and temperature range of - 5 °C to 100 °C. Built-in cooling system prevents over heating of the chamber. The upper and lower temperature range are automatically pre-set with an alarm and automatic overload prevention system. Automatic identification of difference between set and ambient temperature with detection of single heating or cooling heating.