The glow wire test is used to simulate the effect of heat as may arise in malfunctioning electrical equipment, such as with overloaded or glowing components. Test results provide a way of comparing the ability of materials to extinguish flames and their ability to not produce particles capable of spreading fire. The glow-wire apparatus and common test procedure is specified in IEC 60695-2-10.
A finished product or portion thereof is subjected to a glow-wire tip for 30 seconds at a specified temperature to determine if that contact exposure causes the sample to ignite. If the sample ignites the duration of the flame, the maximum height, and if dripping material ignites a layer of tissue below the sample is recorded.
The sample is considered to pass if there is no flame, or if the flame extinguishes within 30 seconds of the glow-wire being removed and the tissue paper is not ignited, unless otherwise specified in the relevant specification.
Test samples should be an entire finished product unless size prevents it from being tested, if you have a question please contact the lab. The part must be at least large enough that if an 8mm circle was drawn on paper, the circle could be completely hidden from view by the part in some orientation. Only one sample is required for the test, though we suggest additional samples be provided in case they are needed. Some specifications requiring this test also require additional samples.
- IEC 60695-2-11 – The Glow Wire Test (GWT) is used when glow wire testing is performed on an end product. The results of this test will be either PASS or FAIL at a given temperature. Passing the test requires that the sample does not ignite or self-extinguishes within 30 seconds after removal of the heated element. Also, the sample may not ignite the tissue paper if drips occur.
- IEC 60695-2-12 – Glow Wire Flammability Index (GWFI) is a property associated with raw material used in the end product. This property is determined by conducting the glow wire test on a test plate of a raw material of a given thickness. The GWFI is the highest temperature at which the material does not ignite or self-extinguishes within 30 seconds after removal of the heated element.
- IEC 60695-2-13 – Glow Wire Ignition Temperature (GWIT) is a property associated with raw material used in the end product. This property is determined by conducting the glow wire test on a test plate of a raw material of a given thickness. The GWIT is the lowest temperature at which the material ignites and burns for longer than 5 seconds while the heated element is in contact with the test plate.
Eason Wang