PURPOSE

This test method is used primarily to determine the heat evolved in, or contributed to, a fire involving products of the test material. Also included is a determination of the effective heat of combustion, mass loss rate, and the time to sustained flaming, and smoke production. These properties are determined on small size specimens that are representative of those in the intended end use.

 This test method is applicable to various categories of products and is not limited to representing a single fire scenario.

 This test method is not applicable to end-use products that do not have planar, or nearly planar, external surfaces.

 SUMMARY

Size and Preparation:

Test specimens shall be 100 by 100 mm in area, up to 50-mm thick, and cut to be representative of the construction of the end-use product. For products of normal thickness greater than 50 mm, the requisite specimens shall be obtained by cutting away the unexposed face to reduce the thickness to 50 mm. For testing, wrap specimens in a single layer of aluminum foil, shiny side toward the specimen, covering the sides and bottom.

 Expose composite specimens in a manner typical of the end-use condition. Prepare them so the sides are covered with the outer layer(s) or otherwise protected.

 Composite and intumescing materials may require special mounting and retaining techniques to retain them adequately within the specimen holder during combustion.

Such mounting techniques include the use of an edge frame in the horizontal orientation, the use of a wire grid in either orientation, or other special mounting procedures suitable to the specimen being tested. Figure shows a wire grid suitable for several types of intumescing specimens. The exact mounting and retaining method used shall be specified in the test report. Assemblies shall be tested as specified above. However, where thin materials or composites are used in the fabrication of an assembly, the presence of an air gap or the nature of any underlying construction often significantly affects the ignition and burning characteristics of the exposed surface. The influence of the underlying layers must be understood and care taken to ensure that the test result obtained on any assembly is relevant to its use in practice. When the product is a material or composite that is normally attached to a well defined substrate, it shall be tested in conjunction with that substrate, using the recommended fixing technique, for example, bonded with the appropriate adhesive or mechanically fixed. Products that are thinner than 6 mm shall be tested with a substrate representative of end use conditions, such that the total specimen thickness is 6 mm or more. In the case of specimens of less than 6 mm in thickness and that are used with an air space adjacent to the unexposed face, the specimens shall be mounted so that there is an air space of at least 12 mm between its unexposed face and the refractory fiber blanket. This is achieved by the use of a metal spacer frame. Conditioning—Specimens shall be conditioned to moisture equilibrium (constant weight) at an ambient temperature of 23 + 3°C and a relative humidity of 50 + 5 %.

 Test Environment

 The apparatus shall be located in a draft-free environment in an atmosphere of relative humidity of between 20 and 80 % and a temperature between 15 and 30°C.

 Report

Report the following information unless specified otherwise in the relevant material or performance standard:

• Heating flux and exhaust system flow rate,
• Number of replicate specimens tested under the same conditions,
• Time to sustained flaming (seconds),
• Heat-release rate (per unit area) curve (kW/ms2),
• Peak, and average values for the first 60, 180, and 300 s after ignition, or for other appropriate periods
• For specimens that do not show sustained flaming, report the above quantities tabulated for periods beginning with the next reading after the last negative rate of heat release reading at the beginning of the test.
• Total heat released by the specimen (MJ/m2)
• Average Dhc,eff for entire test (MJ/kg).
• Curve of Dhc,eff(MJ/kg) (optional).
• Mass remaining after test (g).
• Sample mass loss (kg/m2).
• The average specimen mass loss rate (g/m2-s), computed over the period starting when 10 % of the ultimate specimen mass loss occurred and ending at the time when 90 % of the ultimate specimen mass loss occurred.
• Smoke obscuration. Report the average specific extinction area (m2/kg).
• Difficulties encountered in testing, if any.