Sauermann Kimo Si-HH3 Thermo-Hygrometer Checking humidity levels in building services or HVAC systems needs more than just an RH percentage reading — dew point matters too, since that's where the risk of condensation begins. Absolute humidity and wet bulb temperature are also important for psychrometric calculations, particularly useful when commissioning air handling systems. The Si-HH3 measures and calculates all of these from a single probe, with a free app showing readings on a connected phone. The built-in thermo-hygrometry probe measures temperature from -20°C to 60°C, RH from 0 to 100%, and calculates dew point down to -40°C, alongside absolute humidity, wet bulb temperature and enthalpy. A two-line backlit LCD shows the readings clearly, and a magnetic backing holds the instrument in place on a metal surface in a plant room or AHU enclos