A measure of the spread of flame across the surface of a material without the flame necessarily involving the main body of the material gives an indication of the flammability of the material and its ability to spread the fire and thus endanger life. At present, a large scale test method is used to assess spread of flame on wall and ceiling linings ( BS 476: Part 7) and is commonly used by legislators and specifiers.
采用不测量材料主体上的火焰，而测量材料表面火焰的传播的方法为材料的可燃性，传播火灾而因此危害生命的能力提供了一个指示。目前，大规模的测试被用来评估火焰在墙上和天花板上的传播能力( BS 476: Part 7)并被立法者和***广泛使用。
The material spread of flame along the surface of a product orientated in a vertical plane, is determined by this test method using the apparatus shown below. The test provides data suitable for comparing the performance of essentially flat materials, used primarily as the exposed surface of walls or ceiling.
材料的火焰沿着在***在垂直面上的产品的表面传播，是由使用以下的实验装置的测试方法所确定的。这个测试为比较墙或天花板的表面平整材料的性能提供了适用的数据，这些材料主要是用于墙或者天花板的暴露表面。
The specimen is mounted in a watercooled holder and is exposed to a radiant panel for 10 minutes. In addition, a pilot flame is applied to the bottom corner of the specimen during the first minute of test. The time required for the flame front reach reference marks on the specimen is noted, together with the extent of flame spread at 1 ? minutes and at the end of the test. Observati*** are also made of the burning beh***iour and a suffix “Y” is added to the result if softening or slumping occurs. If more than 6 specimens are required to obtain a result, a suffix “R” is added and if the product is tested in a modified form, a prefix “D” is added.
样品安装在一个水散热的支架上，并在一个辐射板上暴露10分钟。此外，在测试开始后的一分钟内把引燃火焰施加到样品的底角，记下火焰头到达产品上的参考标志所需要的时间，连同火焰在1分30秒和测试终止时的传播的范围记下。
Materials are classified according to test performance as shown in the table below. Class 4 materials are c***idered high risk.
材料根据测试性能分类，如同下表所示。通过Class 4测试的材料被视为高风险
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Classification
分类
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Spread of flame at 1.5 minutes
在1分30秒时的火焰传播
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Final spread of flame
测试结束时的火焰传播
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Limit（限制）
(mm)
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Tolerance for one specimen
每个样品允许的误差(毫米)(mm)
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Limit
(mm)限制（毫米）
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Tolerance for one specimen
(mm)
每个样品允许的误差
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Class 1（1类）
Class 2 （2类）
Class 3（3 类）
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165
215
265
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25
25
25
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165
455
710
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25
45
75
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Class 4（4类）
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exceeding Class 3 limits
超过3级的限制
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Reference lines to assist surface spread of flame classification:
表面火焰传播的分类的辅助参考线如下：
9 specimens is required to supply for test, each 885 mm x 267 mm by thickness as in practice but not exceeding 50 mm. Specimen must be essentially flat.
请提供9块样品用于测试，每个样品的尺寸为885毫米*267毫米，厚度以实际的厚度为准，但不能超过50毫米。样品必须保持平整。