Measurement of smoke density of cables or optical fiber cables burning under defined conditions - Part 2: Test procedure and requirements
1 Scope
This document provides details of the test procedure to be employed for the measurement of the density of smoke emitted from cables burning under defined conditions. It describes the means of preparing and assembling cables for test, the method of burning the cables, and gives recommended requirements for evaluating test results.
2 Normative references
The following documents contain requirements which, through reference in this text, constitute provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
IEC 60695-4 Fire hazard testing - Part 4: Terminology concerning fire tests for electrotechnical products
IEC 60811-203 Electric and optical fibre cables - Test methods for non-metallic materials - Part 203: General tests - Measurement of overall dimensions
IEC 61034-1 Measurement of smoke density of cables burning under defined conditions - Part 1: Test apparatus
ISO/IEC 13943:2000 Fire safety - Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60695-4 and ISO/IEC 13943:2000 apply.
4 Test apparatus
The test procedure defined in this document shall be carried out using the test apparatus, i.e. test enclosure, photometric system and standard fire source, given in IEC 61034-1.
5 Test assembly
5.1 Test sample
The test sample shall consist of one or more test pieces of cable, each 1.00 m ± 0.05 m long, which shall be carefully straightened and then conditioned for at least 16 h at 23°C ± 5°C.
5.2 Cable test piece selection and test sample assembly
5.2.1 Selection of number of test pieces
5.2.1.1 General
The cable diameter shall be measured using the method given in IEC 60811-203. The measurement shall be made at each of three places, separated by at least 1 m.
The average of the three values obtained shall be rounded to obtain the overall diameter. If the calculation gives 5 or more for the second decimal figure, raise the first to the next number; thus, for example, 5.75 is rounded to 5.8 and 5.74 to 5.7.
The overall diameter obtained shall be used for the selection of the number of test pieces.
5.2.1.2 Cables with an overall diameter greater than 5.0 mm
For cables with an overall diameter of greater than 5.0 mm or greater, the number of test pieces required to make up the test sample shall be in accordance with Table 1.
Introduction iv 1 Scope 2 Normative references 3 Terms and definitions 4 Test apparatus 5 Test assembly 6 Test procedure 7 Evaluation of test results 8 Retest procedure 9 Test report Annex A (Informative) Guidance on the principles and use of smoke measurements Annex B (Informative) Recommended performance requirement Bibliography
电缆或光缆在特定条件下燃烧的烟密度测定 第2部分：试验程序和要求 1 范围 本文件描述了用来测定电缆或光缆在特定条件下燃烧时释出的烟密度的试验程序，并详细介绍被试电缆或光缆样品的制备、组装及燃烧方法，推荐有关评定试验结果的要求。 2 规范性引用文件 下列文件中的内容通过文中的规范性引用而构成本文件必不可少的条款。其中，注日期的引用文件，仅该日期对应的版本适用于本文件；不注日期的引用文件，其最新版本（包括所有的修改单）适用于本文件。 IEC 60695-4 电工电子产品着火危险试验 第4部分：着火试验术语（Fire hazard testing—Part 4：Terminology concerning fire tests for electrotechnical products） IEC 60811-203 电缆和光缆 非金属材料通用试验方法 第203部分:通用试验方法 厚度和外形尺寸测量（Electric and optical fibre cables—Test methods for non-metallic materials—Part 203：General tests—Measurement of overall dimensions） IEC 61034-1 电缆或光缆在特定条件下燃烧的烟密度测定 第1部分：试验装置（Measurement of smoke density of cables burning under defined conditions—Part 1：Test apparatus） ISO/IEC 13943：2000 消防安全 词汇（Fire safety—Vocabulary） 3 术语和定义 IEC 60695-4和ISO/IEC 13943：2000界定的术语和定义适用于本文件。 4 试验装置 本文件规定的试验程序应采用IEC 61034-1给定的试验装置，即试验箱、光测装置和标准火源进行。 5 试验准备 5.1 试样制备 试样应由经小心校直的一根成多根1.00 m±0.05 m长的电缆或光缆组成，然后应在23℃±5℃下放置至少16 h。 5.2 电缆或光缆试样根数选择和组装 5.2.1 试样根数的选择 5.2.1.1 通则 电缆或光缆外径应采用IEC 60811-203给出的方法，且应在三处相隔至少1m的地方进行测量。 电缆或光缆外径取三个值的平均值并应修约到一位小数。如果计算得出的第二位小数大于或等于5，则第一位小数应进一位；例如：5.75修约为5.8，5.74修约为5.7。 计算得出的电缆或光缆外径应用于选择试样的数量。 5.2.1.2 电缆或光缆外径大于5.0 mm 电缆或光缆外径大于5.0 mm时，组成试验样品的试样根数应符合表1的规定。 表1 试样根数 电缆或光缆外径（d） 试样根数 d＞40.0 1 20.0＜d≤40.0 2 10.0＜d≤20.0 3 5.0＜d≤10.0 N1a a N1＝45/d根试样。N1值应舍去小数取整数，得出试样根数。 5.2.1.3 电缆或光缆外径小于或等于5.0 mm、大于或等于1.0 mm 电缆或光缆外径小于或等于5.0 mm、大于或等于1.0 mm时，应将7根试样制成一束。组成试验样品的试样束数量（N2）应按公式（1）计算： （1） N2值应舍去小数取整数，得出试样束数量。 每一束应由7根电缆或光缆绞合在一起构成，综合节距在20d～30d之间，然后用直径约为0.5mm的金属丝从中心部位开始每隔100mm绕两圈扎紧（见图1）。 单位为毫米
