1-color pyrometer in the short-wave spectral range for non-contact temperature measurement already from 50°C on metals, ceramics, graphite and many other materials
Pyrometers are necessary when non-contact temperature measurements are required and can take readings several meters away from the target source. Different spectral wavelengths are used depending on the target material such as metals and glass. Special 2-color pyrometers are used for more complex measuring conditions, e.g. if the emissivity of a measuring object is unknown or changes over time, if the measuring object is smaller than the pyrometer's measuring spot size or the measuring conditions change due to dirty lenses, dust and smoke.
Infrared switches (also called hot metal detectors) record the temperature just like an infrared thermometer, but do not output a temperature, but a switching signal when a certain temperature is exceeded or not reached.