DSH 752（IEC 60695）灼热丝火焰定义

Subject: Definition of a flame for glow wire test

Question:

How is the “Corona-Effect” to be interpreted when performing the Glow Wire Test?

Decision:

During the glow wire test (according to the temperature settings required by the standard), the following phenomena can occur:

1. If a brightly shining flame is observed directly at the test specimen (see picture 1), this is a clear indication of an ignition. Some materials show a colourless transparent flame instead of a bright shiny flame. This is considered to be ignition of the test specimen, if the maximum flaming time allowed by the standard is exceeded.

2. Sometimes, a circular corona can be observed around the tip of the glow wire, see picture 2. This corona consists of ionized gas, predominantly blue in colour and is located in the immediate vicinity of the glow wire. This phenomenon is not considered to be ignition of the test specimen, as long as it does not lead to an ignition of the test specimen according to point 1.

3. Furthermore, ionized gasses can sometimes be noticed along the glow wire (see picture 3). This effect is also not considered to be ignition of the test specimen, as long as it does not lead to an ignition of the test specimen according to point 1.

问题：

在进行灼热丝试验时，如何解释“电晕效应”？

决定：

在灼热丝试验过程中（根据标准要求设置温度），可能会出现以下现象：

1、如果在测试样品上能直接观察到明亮的火焰（见下图），就是明确的着火现象。有些材料会表现出无色透明的火焰，而不是明亮闪亮的火焰。如果超过了标准允许的最大燃烧时间，认为样品着火。

2、有时可以在灼热丝尖端周围观察到一个圆形电晕（见下图）。这个电晕圈由电离气体组成，主要是蓝色的，位于灼热丝附近。这种现象只要不像第一点会导致样品着火，就不认为是着火现象。

3、另外，有时能沿着灼热丝看到电离气体（见下图）。这种现象只要不像第一点会导致样品着火，也不认为是着火现象。

提示：

不应考虑“电晕效应”，“电晕效应”不被视为灼热丝测试标准意义上的火焰。

点击下方名片，关注“朱大侠的质检江湖”微信公众号，一起来研究安规吧~