NFPA 270 Standard Test Method for Measurement of Smoke Obscuration Using a Conical Radiant Source in a Single Closed Chamber
NFPA 270 在单一密闭房间使用圆锥型辐射热度量烟模糊度标准试验方法
1.1 Scope.
1.1.1 This shall be a fire-test-response standard.
1.1.2 This test method shall provide a means of measuring smoke obscuration resulting from subjecting essentially flat materials, products, or assemblies (including surface finishes) not exceeding 25 mm in thickness, to specified levels of thermal irradiance from a conical heater, in a single closed chamber, in the absence or presence of a pilot flame, and when placed in a horizontal orientation.
1.1.3 The principal fire-test-response characteristic obtained from this test method shall be the specific optical density of smoke from the specimens tested, which is obtained as a function of time, for a period of 10 minutes.
1.1.4 Other fire-test-response characteristics shall also be permitted to be determined.
1.1.5 An optional fire-test-response characteristic measurable with this test method shall be the mass optical density, which is the specific optical density of smoke divided by the mass lost by the specimens during the test.
1.1.6 This test method shall be based on ISO 5659-2, Determination of Specific Optical Density by a Single-Chamber Test, and shall provide equivalent results to ISO 5659-2.
1.1.7 The fire-test-response characteristics obtained from this test shall be specific to the specimen tested, in the form and thickness tested, and shall not be inherent properties of the material, product, or assembly.
1.1.8* This test method shall not provide information on the fire performance of the test specimens under fire conditions other than those conditions specified in this test method.
1.1.9 This standard shall measure and describe the response of materials, products, or assemblies to heat and flame under controlled conditions, but shall not by itself incorporate all factors required for fire hazard or fire risk assessment of the materials, products, or assemblies under actual fire conditions.
1.1.10* Fire testing of products and materials is inherently hazardous, and safeguards for personnel and property shall be employed in conducting these tests.
1.1.11 This standard shall not purport to address all of the safety problems, if any, associated with its use.
1.1.12 It shall be the responsibility of the user of this standard to establish the necessary safety and health practices and determine the applicability of regulatory limitations prior to use. A.1.1.8 For limitations of this test method, see 1.3.3. A.1.1.10 This test method is known to involve hazardous materials, operations, and equipment as described in 5.2.2, 5.2.3, and 9.7.2.
NFPA 270 Standard Test Method for Measurement of Smoke Obscuration Using a Conical Radiant Source in a Single Closed Chamber provides fire test labs with a means of measuring smoke obscuration of essentially flat materials, products, or assemblies (including surface finishes) up to 25mm thick, when exposed to specified levels of thermal irradiance in a single closed chamber. This test method is based on ISO 5659-2, Determination of Specific Optical Density by a Single-Chamber Test, and provides equivalent results to ISO 5659-2.
The principal fire-test-response characteristic obtained from using NFPA 270 is the specific optical density of smoke from the specimens tested. An optional fire-test-response characteristic measurable with this method is the mass optical density, which is the specific optical density of smoke divided by the mass lost by the specimens during the test.
The 2008 edition deleted secondary definitions of "ignition", "smoke obscuration", and "specimen". (Softbound, 29 pp., 2008)