Measuring device for measuring air humidity, material equilibrium moisture, and measuring the dew point in compressed air systems. Humidity profiles can be recorded and analyzed and displayed graphically as well as in tabular form. Wireless, meaning that measurement data can be transmitted via radio, the testo 635-2 can display up to 3 temperature or humidity sensors. Selectable user profiles, i.e., a function key layout and menu navigation tailored to the application, allow for intuitive operation. Material moisture can be displayed directly due to the special sensors. Characteristic curves for various materials can be stored in ComSoft and transferred to the measuring device. To analyze moisture on ceilings and walls, the testo 635 directly shows the dew point distance between room air and wall surface. For checking the dew point in compressed air systems, precision sensors down to -60°C tpd are available. The moisture sensor developed by Testo itself is proven worldwide and offers outstanding characteristics in terms of precision, long-term stability, temperature resistance, and robustness.