The Testo 845-HM (0563 8451) Infrared Thermometer is a compact infrared thermometer with switch optics for the non-contact measurement of surface temperatures and humidity. The switchable optics for far-field and close focus measurements make it possible to measure at short as well as at greater distances. Measurements in the far-field are taken at an optical resolution of 75:1. This allows surface temperatures to be measured accurately even at greater distances to the measurement object. At a distance of 1.2 meters to the measurement object, the measurement point diameter is only 16 mm. A cross laser marks the measurement site exactly.

For measurements at a short distance to the measurement object, the close focus optics offer a measurement point diameter of only 1 mm at a distance of 70 mm. Two laser points mark the measurement area. Measurements can also be carried out by connecting additional probes. The limit values can be individually stored in the instrument; as soon as these upper and lower limit values are violated, an audible and an optical signal are given.

The 845-HM Infrared Thermometer includes an integrated humidity module for making accurate surface moisture measurements.