The Testo 645 (0560 6450) 2-Channel Thermo-Hygrometer for Industry is a highly accurate thermal hygrometer that has two probe inputs for the connection of an extensive range of probes. Channel 1 supports temperature Type K/J/S, NTC; channel 2 connects to combination humidity/temperature probe or temperature probe Pt 100. The 645 automatically displays the measurement parameters temperature, relative humidity, dewpoint, pressure dewpoint, absolute humidity, degree of humidity and enthalpy, and additionally presents the current values, the last measured values, min., max. and mean values at the press of a button.