What does ATC- temperature calibration mean?

The ATC function is designed to compensate for temperature differences, due to physics, which may occur between the circulator and a defined measuring point. When using a reference thermometer, the actual temperature can be determined at any measuring point (circulator bath or external application).The ATC function calibrates the circulator control to the reference value. The internal temperature sensor as well as the external sensor (if an external sensor connection exists) possible.