NFPA 258-2001 Recommended Practice for Determining Smoke Generation of Solid Materials

NFPA 258-2001 Recommended Practice for Determining Smoke Generation of Solid Materials. 3.4 Specimen Mounting. 3.4.1 All specimens should be covered across the back, along the edges, and over the front-surface periphery with a single sheet of aluminum foil 0.0010 in. to 0.0016 in. (0.025 mm to 0.040 mm) thick. 3.4.2 Care should be taken not to puncture the foil or to intro- duce unnecessary wrinkles during the wrapping operation. 3.4.3 Foil should be folded in a way that minimizes loss of melted material at the bottom of the holder. 3.4.4* Excess foil along the front edges should be trimmed off after mounting. A flap of foil should be cut and bent forward at the spout to permit flow from melting specimens. 3.4.5 All specimens should be backed with a sheet of asbestos millboard. (See Section 2.4.) 3.4.6 The specimen and its backing should be secured with a spring and retaining rod. A modified, C-shape retaining rod should be used with specimens that are 5 / 8 in. to 1 in. (15.9 mm to 25.4 mm) thick. 3.4.7 Flexible specimens should not be compressed below their normal thickness. 3.4.8 The intent of this test method should be to maintain the prescribed exposure conditions on the specimen for the test duration. If during either the flaming or the nonflaming expo- sure an excess of melted material overflows the trough, the specimen area should be reduced. For example, if the area is reduced to 1 1 / 2 in. wide × 3 in. high (38.1 mm wide × 76.2 mm high) and is centrally located, the appropriate area should be used in calculating D s . (See Section 5.1.) Chapter 7 Referenced Publications 7.1 The following documents or portions thereof are refer- enced within this recommended practice and should be con- sidered as part of its recommendations. The edition indicated for each referenced document is the current edition as of the date of the NFPA issuance of this recommended practice. Some of these documents might also be referenced in this rec- ommended practice for specific informational purposes and, therefore, are also listed in Appendix E. 7.2 NFPA Publication. National Fire Protection Association, 1 Batterymarch Park, P.O. Box 9101, Quincy, MA 02269-9101. NFPA 270, Standard Test Method for Measurement of Smoke Obscuration Using a Conical Radiant Source in a Single Closed Chamber, 1998 edition. NFPA 258 pdf download.