This part of ISO 18434 provides an introduction to the application of infrared thermography (IRT) to machinery condition monitoring and diagnostics, where “machinery” includes machine auxiliaries such as valves, fluid and electrically powered machines, and machinery related heat exchanger equipment. In addition, IR applications pertaining to machinery performance assessment are addressed. This part of ISO 18434: ⎯ introduces the terminology of IRT as it pertains to condition monitoring and diagnostics of machines; ⎯ describes the types of IRT procedures and their merits; ⎯ provides guidance on establishing severity assessment criteria for anomalies identified by IRT; ⎯ outlines methods and requirements for carrying out IRT of machines, including safety recommendations; ⎯ provides information on data interpretation, and assessment criteria and reporting requirements; ⎯ provides procedures for determining and compensating for reflected apparent temperature, emissivity and attenuating media. This part of ISO 18434 also encompasses the testing procedures for determining and compensating for reflected apparent temperature, emissivity and attenuating media when measuring the surface temperature of a target with a quantitative IRT camera.