The HVACR tester is used in HVAC technology to monitor humidity and temperature. The measured values are output as a standard signal by the HVACR tester. Air humidity and temperature are accurately determined in this compact HVACR tester via a semiconductor component. For commissioning, the HVACR tester is supplied with a DC voltage. The measured values are output via a two-wire cable. All connections are made via screwed contacts in the waterproof IP 65 housing. In addition to the output of the measuring signal as a 0 ... 10 V signal, the measured values can be output via the RS485 interface. This function is useful if several monitoring points are to be linked to each other during your house surveillance.