Introduction to Glow-Wire Testing Equipment
Glow-wire testing equipment is pivotal in ensuring safety standards. This apparatus evaluates the material’s capacity to extinguish flames and its potential to prevent fire-spreading particles. The standardized procedure for glow-wire testing is detailed in IEC 60695-2-10.
Testing Process Overview
A segment of the final product is exposed to a glow-wire tip at a predetermined temperature for 30 seconds. The primary objective is to ascertain if this exposure ignites the sample. In cases where ignition occurs, the test records the flame’s duration, maximum height, and whether any dripping material ignites a layer of tissue beneath the sample.
Criteria for Passing the Test
The sample passes if there is no flame or if any flame extinguishes within 30 seconds after the glow-wire’s removal, provided that the tissue paper does not ignite. Specific criteria may vary depending on the relevant specification.
Sample Requirements
Ideally, test samples should be complete finished products unless their size makes testing impractical. If unsure, consult with the laboratory. The part must be sufficiently large to obscure an 8mm circle drawn on paper in some orientation. Although one sample suffices, additional samples are recommended in case further testing is necessary. Certain specifications may mandate extra samples.
Standards and Indices
- IEC 60695-2-11: This standard applies when conducting glow-wire tests on end products, yielding results of either PASS or FAIL at a specified temperature. To pass, the sample must not ignite or must self-extinguish within 30 seconds post-removal of the heated element. Additionally, any drips should not ignite the tissue paper.
- IEC 60695-2-12: The Glow Wire Flammability Index (GWFI) pertains to raw materials used in end products. This index is determined by performing glow-wire tests on a test plate made from raw material of a specified thickness. GWFI represents the highest temperature at which the material does not ignite or self-extinguishes within 30 seconds after removing the heated element.
- IEC 60695-2-13: The Glow Wire Ignition Temperature (GWIT) also relates to raw materials used in end products. This property is identified by conducting glow-wire tests on a raw material test plate of a certain thickness. GWIT signifies the lowest temperature at which the material ignites and burns for more than five seconds while in contact with the heated element.
