UL-10D:2014 pdf free download – STANDARD FOR SAFETY Fire Tests of Fire Protective Curtain Assemblies.
7.2 Uniformity of temperature distribution
7.2.1 At any time after the first 10 minutes of fire exposure, the temperature rise indicated by any of the thermocouples used to determine the furnace temperature shall not differ from each other by more than 270° F (150°C). With test constructions where either the test sample or any associated construction incorporates combustible materials that produce flaming within the furnace or where excess air drawn into the furnace is identified as causing localized heating or cooling of one or more of the furnace thermocouple hot junctions, the deviation of temperature rise from each other recorded by the thermocouples so affected shall not exceed 450°F (250°C).
8 Furnace Temperatures
8 effective August 31, 2015
8.1 The temperatures of the test exposure shall be deemed by a minimum of three thermocouples and no fewer than nine thermocouples per 100 square feet of test assembly symmetrically disposed within the furnace and distributed to show the temperature near all parts of the test assembly. The thermocouples shall be protected by a sealed porcelain tube having a 3/4 in (19.1 mm) outside diameter and 1/8 in (3.2 mm) wall thickness or, as an alternate, in the case of base-metal thermocouples, protected by a 1/2 in (12.7 mm) wrought-steel or wrought-iron pipe of standard weight.
8.2 The junction of the thermocouples shall be initially located 6 in (152 mm) from the exposed face of the test assembly or from the subassembly in which the test assembly is installed. During the fire exposure, if the movement of the test sample causes the sample’s distance to the thermocouple junction to vary, the location of the junction shall be reset to 6 in (152 mm) at intervals not exceeding 10 minutes during the first 30 minutes of the test. Thereafter, the intervals are to be increased to not more than 30 minutes.
8.3 The temperatures shall be read at intervals not exceeding 1 minute.
8.4 The accuracy of the furnace control shall be such that the area under the time-temperature curve, obtained by averaging the results from the thermocouple readings, is within 10 percent of the corresponding area under the standard time-temperature curve for fire tests of 1 hour or less duration, within 7.5 percent for those over 1 hour and not more than 2 hours, and within 5 percent for tests exceeding 2 hours in duration.
8.5 For a summary of the accuracies for the various rating periods, see Appendix A.
9 Furnace Pressure
9 effective August 31, 2015
9.1 The pressure in the furnace, relative to atmosphere, is to be measured by a probe at the top of the fire protective curtain assembly and a probe at a location 40 in (1 m) above the sill. The probes are to be positioned horizontally in the furnace without a change in vertical elevation of the probes or tubing within the furnace.
9.2 Each pressure probe is to be either as described in Figure 9.1 or constructed from 1/2 in (12.7 mm) diameter stainless steel tube with a welded, closed end, and incorporating nine radial, 1/16-in (1.6-mm) diameter holes spaced equidistance around the tube’s perimeter. Each probe is to be located so that the center line of the sensing holes are positioned 6 ±1 in (152±2.5 mm) from the surface of the exposed face of the test assembly and a minimum of 18 in (457 mm) from the edges of the furnace.