关于燃烧的历史：

-UL request needle flame (open fire) test to rate flammability per UL-94 Vxx  

UL 要求针焰（明火）试验以评定UL-94的易燃性。

- industry recognized that glowing wires ( caused by electrical overload) may put plastic materials on open fire。行业公认的灼热丝（由电气过载引起）可能使塑料材料暴露在明火上。

-France railway started with glow wire tests first and specified two sets of test: (法国铁路公司率先进行了发光线试验，并规定了两组试验：)

 GWFI flammability index : no ignition (<2sec)  可燃性指数：无点火（小于2秒）。

在这种情况下，它表示该物质在2秒内不会点火。

GWIT ignition temperature :define the GW temperature when burning starts >30s (rating defines when materials in no longer good）

GWIT点火温度：定义燃烧开始时的GW温度（超过30秒）（评级定义材料不再良好时的温度），

简而言之，GWIT描述的是物质开始燃烧所需的最低温度，并且燃烧持续时间超过30秒。

-IEEE 60335 took these experience into a standard

-------------------------------

GWFI

the highest temperature at which, in 3 consecutive tests, the flame or glow of the test specimen is extinguished within 30 seconds of the glow wire being removed, without the underlying tissue paper being set on fire by burning drops or particles (in accordance with the IEC 695-2-1/2 standard) 在连续3次测试中，测试试样的火焰或辉光在辉光丝被移除后的30秒内熄灭，且底层纸不会被燃烧滴或颗粒点燃（符合IEC 695-2-1/2标准），此时达到的最高温度。

WFIT 

The temperature 25c higher than the maximum temperature of the glow wire at which no flame develops in 3 consecutive tests (in accordance with the IEC  695-2-1/3 standard); where the maximum allowed flame development time is 5 seconds.

在连续3次测试中，不产生火焰的温度，即辉光丝最大温度加25℃（符合IEC 695-2-1/3标准），其中允许的最大火焰发展时间为5秒。