NFPA 265-1998 Standard Method of Fire Tests for Evaluating Room Fire Growth Contribution of Textile Wall Coverings.
4-1 Fire Room Environment. 4-1.1 The test building in which the fire room is located shall have vents for the discharge of combustion products and have provisions for fresh air intake, so that no oxygen-deficient air shall be introduced into the fire room during the test. Prior to the start of the test, the ambient air at the mid-height entrance to the compartment shall have a velocity of less than 100 ft/ min (0.5 m/sec) in any direction, as measured at a horizontal distance of 3 ft (0.91 m) from the center of the doorway. The building shall be of adequate size, so that there shall be no smoke accumulation in the building below the level of the top of the fire compartment. 4-1.2 The ambient temperature in the test building at loca- tions around the fire compartment shall be above 40°F (4°C), and the relative humidity shall be less than 75 percent for the duration of the test. 4-1.3 The following ambient conditions shall be maintained: (a) The ambient temperature in the fire room, measured by one of the thermocouples in 5-1.3.2, shall be in the range of 64°F to 75°F (18°C to 24°C). (b) The ambient relative humidity in the fire room shall be 50 percent ± 5 percent.
5-1.3* Thermocouples. Bare Type K Chromel Alumel ® ther- mocouples, 20 mil (0.5 mm) in diameter, shall be used at each required location. The thermocouple wire within 0.5 in. (13 mm) of the bead shall be run along expected isotherms to minimize conduction errors. The insulation between the Chromel and Alumel wires shall be stable to at least 2000°F (1100°C), or the wires shall be separated. 5-1.3.1 A thermocouple shall be located in the interior plane of the door opening on the door centerline, 4 in. (102 mm) from the top. (See Figure 5-1.2.) 5-1.3.2 Thermocouples shall be located at six positions, 4 in. (102 mm) below the ceiling. These thermocouples shall be located at the center of the ceiling, at the center of each of the four ceiling quadrants, and directly over the center of the igni- tion burner. The thermocouples shall be mounted on sup- ports or shall penetrate through the ceiling with their junctions 4 in. (102 mm) away from a solid surface (see Figure 5-1.2). There shall be no attachments to the test specimens. Any ceiling penetration shall be just large enough to permit passage of the thermocouples. Spackling compound or ceramic fiber insulation shall be used to backfill the holes around the thermocouple wire. 5-1.4 Two paper target flashover indicators shall be placed on the floor of the test room (see Figure 5-1.4). The targets shall consist of a single piece of newsprint crumpled into an approximate 6-in. (152-mm) diameter ball.NFPA 265 pdf download.