This part of IEC 60721 is a technical report dealing with the correlation and transformation of the conditions given in IEC 60721‑3 to the environmental tests defined in IEC 60068‑2. It is an introduction to the series of publications IEC 60721‑4 which aims at providing the specification writer with guidance together with a set of easy-to-use tables to help correlate and transform these conditions.

The purpose of this technical report is to recommend the environmental tests which may be chosen to demonstrate the capability of a product to function or survive satisfactorily as specified in the relevant specification when subjected to the climatic and dynamic conditions given by IEC 60721‑3. These test severities, including their suggested duration, are not intended to demonstrate the reliability of the product, guidance for which should be sought from the publications concerning the field of availability, reliability, maintainability and maintenance support.

Whilst it may not be possible to recommend severities for all types of product, locations and applications, it is possible to suggest tests which are adequate for the majority. Guidance information has been included with the suggested tests which describes how the severities have been chosen. The rationale contained in this guidance may also be used to help modify test severities when the conditions found in IEC 60721‑3 do not adequately describe a particular environment or application.