【国外标准】 Standard Test Method for Heat Release, Flame Spread, Smoke Obscuration, and Mass Loss Testing of Insulating Materials Contained in Electrical or Optical Fiber Cables When Burning in a Vertical Cable Tray Configuration

5.1 This test method provides a means to measure a variety of fire-test-response characteristics associated with heat and smoke release and resulting from burning the materials insulating electrical or optical fiber cables, when made into cables and installed on a vertical cable tray. The specimens are allowed to burn freely under well ventilated conditions after ignition by means of a propane gas burner. The ignition source used in this test method is also described as a premixed flame flaming ignition source in Practice E3020, which contains an exhaustive compilation of ignition sources.5.2 The rate of heat release often serves as an indication of the intensity of the fire generated. General considerations of the importance of heat release rate are discussed in Appendix X1 and considerations for heat release calculations are in Appendix X2.5.3 Other fire-test-response characteristics that are measurable by this test method are useful to make decisions on fire safety. The test method is also used for measuring smoke obscuration. The apparatus described here is also useful to measure gaseous components of smoke; the most important gaseous components of smoke are the carbon oxides, present in all fires. The carbon oxides are major indicators of the completeness of combustion and are often used as part of fire hazard assessment calculations and to improve the accuracy of heat release measurements.5.4 Test Limitations: 5.4.1 The fire-test-response characteristics measured in this test are a representation of the manner in which the specimens tested behave under certain specific conditions. Do not assume they are representative of a generic fire performance of the materials tested when made into cables of the construction under consideration.5.4.2 In particular, it is unlikely that this test is an adequate representation of the fire behavior of cables in confined spaces, without abundant circulation of air.5.4.3 This is an intermediate-scale test, and the predictability of its results to large scale fires has not been determined. Some information exists to suggest validation with regard to some large-scale scenarios.1.1 This is a fire-test-response standard.1.2 This test method provides a means to measure the heat released and smoke obscuration by burning the electrical insulating materials contained in electrical or optical fiber cables when the cable specimens, excluding accessories, are subjected to a specified flaming ignition source and burn freely under well ventilated conditions. Flame propagation cable damage, by char length, and mass loss are also measured.1.3 This test method provides two different protocols for exposing the materials, when made into cable specimens, to an ignition source (approximately 20 kW), for a 20 min test duration. Use it to determine the heat release, smoke release, flame propagation and mass loss characteristics of the materials contained in single and multiconductor electrical or optical fiber cables.1.4 This test method does not provide information on the fire performance of materials insulating electrical or optical fiber cables in fire conditions other than the ones specifically used in this test method nor does it measure the contribution of the materials in those cables to a developing fire condition.1.5 Data describing the burning behavior from ignition to the end of the test are obtained.1.6 This test equipment is suitable for measuring the concentrations of certain toxic gas species in the combustion gases (see Appendix X4).1.7 The values stated in SI units are to be regarded as standard (see IEEE/ASTM SI-10). The values given in parentheses are mathematical conversions to inch-pound units that are provided for information only and are not considered standard.1.8 This standard measures and describes the response of materials, products, or assemblies to heat and flame under controlled conditions, but does not by itself incorporate all factors required for fire hazard or fire risk assessment of the materials, products or assemblies under actual fire conditions1.9 Fire testing is inherently hazardous. Adequate safeguards for personnel and property shall be employed in conducting these tests.1.10 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.11 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.