UL 1565-2013 pdf download

UL 1565-2013 pdf download.Positioning Devices.
C2.4 Collection hood and exhaust duct
C2,4.1 The collection hood shall be installed centrally above the test specimen. The lace dimensions of the hood shall be at least 2.4 by 2.4 m (8 by 8 feet), and the depth shall be 1.07 m (3.5 feet). The hood shall exhaust Into a plenum having a 0.9 by 0.9 m (3 by 3 foot) cross section (see Figure C.3. Collection Hood and Exhaust Duct). The lower edge of the collection hood shall be positioned so that the hood collects all products of combustion and shall be not less than 2.1 m (7 feet) above the top edge of the test enclosure.
C2.4.2 The exhaust duct connected to the plenum shall be 406 mm (16 indies) in diameter and shall have a circular aperture of 305 mm (12 inches) at its entrance. The duct shall run horizontally at least 4.05 m (13.3 feet) downstream from the last turn in the duct prior to location of instrumentation, in order to provide for a fully developed gas flow. Mixing vanes shall be installed in the duct if concentration gradients are found to exist. The outlet of the exhaust duct shall be connected to an exhaust plenum containing smoke abatement equipment.
C2.4.3 The exhaust system shall have sufficient draft to collect all products of combustion developed by the burning sample. The exhaust flow shall be capable of being varied from a minimum of 0,47 to 2.4 cubic meters per second (1000 to 5000 cubic feet per minute).
C2.4.4 An alternate exhaust system design may be used lilt has been shown to produce equivalent results. Equivalency is demonstrated by meeting the requirements specified in Clause C3, Pretest calibration.
C2.6 Gas sampling and analysis equipment
C2.6.1 A stainless steel gas sampling tube shall be located 152 ±25 mm (6 ±1 inch) downstream from the bi-diroctional probe. for determining the oxygen concentration of the exhaust gas as a function of time. A filter and cold t rap shall be placed in-line ahead of the analyzer to remove parliculates and water. The oxygen analyzera shall be of the paramagnetic type and shall be capable of measuring the oxygen concentration in the range from 0 to 21 percent with an accuracy of ±0.2 percent of oxygen concentration. The signal from the oxygen analyzer shall be within 10 percent of its final value within 30 seconds after introducing a step change in composition of the gas stream flowing past the inlet to the sampling tube.
aAn analyzer found acceptable for this purpose is Beckman Instrument model 755 Paraniagnetic Type Oxygen Analyzer.
C2.7 Smoke measuring Instruments
C2.7.1 The photometer system shall consist of a light source and photoelectric cell that shall be mounted on a horizontal section of duct at a point where it is preceded by a straight run of duct at least 12 diameters or 4.8 m (16 feet) to ensure a nearly uniform velocity of flow across the duct cross section. The photometer system shall not be positioned at another location except where the alternative position has been shown to provide equivalent results. The light beam shall be directed along the diameter of the duct. A photoelectric cell, whose output is directly proportional to the amount of light recerved, shall be mounted opposite the light source. It shall be connected to a recording device accurate to within ±1 percent of full-scale for indicating changes in the attenuation of incident light resulting from the passage from smoke, particulate and other effluents. The distance between the light source lens and the photocell lens shall be 914 ±51 mm (36 ±2 inches). The cylindrical light beam shall pass through 76 mm (3 inch) diameter openings at the top and bottom of the 406 mm (16 inch) diameler duct, with the resultant light beam centered on the photocell.
C2.7.2 The output signal from the photoelectric cell shall be processed into a continuous recod of smoke obscuration from which optical density and smoke release rate shall be calculated
C2.8 Data acquisition
C2.8.1 A digital data acquisition system shall be used to collect and record oxygen analyzer measurements, pressure gauge measurements, temperatures. and smoke measurements. The Speed and capacity of the data system shall be sufficient to collect the data every 5 seconds or less.
C3 Pretest calibration
C3.1 Oxygen analyzer
C3.1.1 The oxygen analyzer shall be zeroed and spanned. The analyzer shall be zeroed by introducing 100 percent nitrogen gas to the instrument at the same pressure and flow rate as set for the sampling of gases. The analyzer shall be spanned by introducing ambient duct air via the sampling probe and adjusting the span to 20.95 percent oxygen. The spanning-and-zeroing process shall be continued until adjustment-free accuracy is obtained.