scope:

This guideline provides information for the appropriate performing of temperature measurements using radiation temperature measuring devices. These instruments permit the temperature of an object to be measured without contact, making use of the laws of optics and radiation physics.

Basic knowledge of temperature measurement using contact thermometers is assumed. The theoretical principles of radiation thermometry and technical solutions relating to instrumentation and circuits, are dealt with only to the extent necessary for understanding the guideline.

All sections contain references to further literature. The relevant textbooks and compilations, journal articles, conference papers, national and international standards or guidelines, emissivity tables and corporate publications are listed together in the Bibliography.

Numerous examples from technical practice are quoted, in order to assist in the correct or optimal use of radiation temperature measuring devices.

Section 2 discusses criteria that allow a preliminary decision to be made as to whether the use of a radiation thermometric measuring systems is practical or possible.

Section 3 describes the fundamentals of radiation temperature measurement, including the connection between temperature, emissivity and radiance. Their understanding, together with the various types of radiation thermometers, line scanners and thermo-graphic devices described in Section 4 to Section 6, is an essential prerequisite for the selection of an optimal radiation temperature measuring device for the special conditions of a particular measurement task.

Possible error sources in temperature measurements that rely on non-contact radiation thermometry, in particular the effect of the measured object's emissivity and of the ambient radiation temperature, are described in detail.