IEC 60695-2-12: glow wire flammability index test method for materials
IEC 60695-2-12 is a test method for finding the glow-wire flammability index (GWFI) of insulating materials to be used in end products. Simply put, the GWFI is the highest temperature at which three samples of material at the relevant thickness pass the glow-wire test. Knowing the GWFI of a material can help when selecting which plastic materials to use in the manufacturing of a product.
Rather than a whole product being tested, the GWFI test is conducted on a number of representative specimens of the material, which have been fabricated in an appropriate way. These specimens should represent every thickness which is to be considered, and be of an appropriate size. The test procedure is carried out as in 60695-2-11, but uses a range of temperatures set out in this standard.
The GWFI is the highest temperature at which three samples pass the test. The index is expressed as temperature/sample thickness e.g.: 850/3.0