The new wireless thermal imaging camera for smartphones, testo 860i, is ideally suited for quick spot checks in the HVAC industry, maintenance, buildings, and many other applications, thanks to its easy operation and display in the testo Smart App. The testo 860i allows for simple and rapid determination of Delta T (temperature difference) in thermal images through application-specific measurement functions: DeltaHeat for quickly measuring the spread of supply and return temperatures at radiators, and DeltaCool for quickly determining the temperature difference in refrigeration and air conditioning systems. Additionally, the moisture mode function assists in assessing the risk of mold in indoor spaces. In maintenance, the thermography measurement function quickly and easily identifies hotspots and Delta T. The operation of the testo 860i, the display of thermal images and temperature differences, as well as documentation, is done through the testo Smart App – simple, fast, and smart. The testo 860i can be used flexibly, either with one-handed operation directly attached to a smartphone or tablet, or separately. Furthermore, its high practicality, robustness, and rechargeable lithium battery with long usage time make the testo 860i a reliable companion.