The IEC 60068 series includes a series of methods for environmental testing along with their appropriate severities, and prescribes various atmospheric conditions for measurements and tests designed to assess the ability of specimens to perform under expected conditions of transportation, storage and all aspects of operational use. Although primarily intended for electrotechnical products, this standard is not restricted to them and may be used in other fields where desired. Other methods of environmental testing, specific to the individual types of specimen, may be included in the relevant specifications.
The framework of environmental test tailoring process is given in order to assist the production of test specifications with appropriate tests and test severities.
The IEC 60068 series provides a series of uniform and reproducible environmental, climatic, dynamic and combined tests, performed and measured under standard atmospheric conditions, for those preparing specifications and those engaged in the testing of products.
These test methods are based upon available international engineering experience and judgement and are primarily designed to provide information on the following properties of specimens:
a) the ability to operate within specified limits of temperature, pressure, humidity, mechanical stress or other environmental conditions and combinations of these conditions;
b) the ability to withstand conditions of transportation, storage and installation.
NOTE 1 The IEC 60721 series provides a system for classification of environmental conditions and gives relevant definitions. The tests in this standard permit the comparison of the performance of sample products. To assess the quality or useful life of a given production lot, the test methods should be applied in accordance with a suitable sampling plan and may be supplemented by appropriate additional tests, if necessary.
NOTE 2 ISO defines “quality” as the degree to which a set of inherent characteristics fulfils requirements..
NOTE 3 “Useful life”: under given conditions, the time interval beginning, at a given instant of time, and ending when the failure intensity becomes unacceptable or when the item is considered unrepairable as a result of a fault.
To provide tests appropriate to the different intensities of an environmental condition, some of the test procedures have a number of degrees of severity.
These different degrees of severity are obtained by varying the time, temperature, air pressure or some other determining factor, separately or in combination.
As the tests and their degrees of severity should be based on real environmental conditions that a particular specimen might encounter, the framework and the necessary phases for the environmental test tailoring process are provided. The test tailoring process may be used to produce the required relevant test specification for the particular specimen.
