The built-in measuring instrument can be connected to up to four external temperature and humidity modules. The temperature measurement range for the sensors of the built-in measuring instrument is from 0.0 to 50.0 °C, and the humidity measurement range is from 0.0 to 99.9 % relative humidity. The power supply is provided via a mains connection of 110 - 220 V AC. The integrated sensor supply can provide the connected sensors with 12 or 24 V DC. Once the sensors are connected, they are automatically recognized. Communication between the sensor modules and the built-in measuring instrument occurs via an analog 4 - 20 mA signal. If multiple sensors are connected, the average measurement value of all sensors is displayed. Thus, the built-in measuring instrument is used in event halls, restaurants, or public buildings to monitor environmental conditions. The installation of the built-in measuring instrument and the sensor module is done on a wall. If needed, the built-in measuring instrument can be mounted on a monitor bracket with mounting dimensions of 75 x 75 mm for optimal alignment. Optionally, the built-in measuring instrument can be equipped with an ISO calibration certificate.