This Technical Specification applies to radiation thermometry. It defines the technical data, i.e. metrological data to be given in data sheets and operating instructions for radiation thermometers with one wavelength range and one measurement field, to ensure that the data and terminology are used consistently. Technical data for radiation thermometers are frequently given using terms whose meaning is not clear and therefore open to misinterpretation. Moreover, the data are given for measuring conditions which are not standardised. Often, influence parameters and mutual interdependencies of technical data are not given. As a result, the user cannot easily compare the technical design and performance data of radiation thermometers and tests for compliance with the manufacturer’s specifications are difficult to carry out. The purpose of this Technical Specification is to facilitate comparability and testability. Therefore, unambiguous definitions are stipulated for stating technical data under standardised measuring conditions. NOTE 1 Infrared ear thermometers are excluded from this Specification. NOTE 2 It is not compulsory for manufacturers and sellers of radiation thermometers to include all items given in this Specification for a specific type of radiation thermometer. Only the relevant data should be stated and should comply with this Specification.