BS EN 60212:2011 pdf free.Standard conditions for useprior to and during thetesting of solid electricalinsulating materials.
BS EN 60212 The recommended standard conditions of temperature and humidity (or liquid immersion) forpreconditioning,conditioning and testing are given in Tables 2 and 3. Parameters should becarefully chosen so that treatment does not cause ageing in a test specimen.
When preconditioning is required，one of the standard atmospheres or one of the dry-hotconditions given in Table 2 may be used for a time specified in the material specification,(e.g.24 h± 2 h). lt is usual to specify (55±2)°C with a relative humidity of less than 20 %.
Preconditioning can be necessary in order to eliminate the effects of stress appearing afterthe moulding process of some plastic materials or as a drying treatment before the testprocedure starts.The preconditioning shall normally be handled in a different environment.
The environment surrounding the sample (such as oil) shall be defined such that it does nothave a deleterious effect on the sample’s properties. There may be more than onepreconditioning environment required to remove previous history and maximize reproducibilityof results. lmmersion in oil/liquid is only needed if testing is required to be undertaken in aliquid. A preconditioning fluid will have an influence on the test properties so furtherconditioning may be needed before testing and a recovery procedure required, as given inIEC 60068-1.The property of the sample will change through the time frame of the test unlessit is correctly prepared beforehand.
The period of conditioning should be specified in the relevant material standard or testmethod.The period of conditioning will usually depend upon the type of material being tested.
In general, it is not intended that the period of conditioning shall be sufficient to enable thespecimens to reach equilibrium with the surrounding atmosphere. The rate at whichequilibrium is reached depends largely upon the nature and dimensions of the test specimens.Consequently，the period of exposure necessary to obtain equilibrium may in some cases(e.g. thin paper) be only a matter of a few minutes, but in others(such as hard rubber) it maybe many months. lt is recommended that periods of conditioning be selected from the list given in Table 4.BS EN 60212 pdf download.