UL 217 UL268 Smoke alarm test box UL Smoke box
UL UL 217 UL268 Smoke alarm test box UL Smoke box
APPENDIX B – TYPICAL SENSITIVITY SMOKE TEST CHAMBER CONSTRUCTION
B1 Construction
B1.1 The visible smoke/aerosol obscuration (optical density) in the test compartment is to be measured by means of a DC type microammeter having a maximum internal resistance of 100 ohms and full scale
reading of 100 mA used with a barrier type selenium photovoltaic cell, enclosed in a hermetically sealed case.a An equivalent meter consists of a digital voltmeter having a minimum input impedance of 10
megohms in parallel with a 100 ohms resistance, and a 500 ohms potentiometer. The meter and cell shall be used in conjunction with the light produced by a tungsten filament automotive type lamp (such as a prefocused spotlight bulb) energized from a constant current source at half rated voltage to provide a light beam of uniform flux density. The photoelectric cell and lamp shall be spaced 1.524 m (5.0 ft.) apart. Refer to Appendix C for equations to be used.
B1.2 A measuring ionization chamber (MIC)b is to be used to measure the relative buildup of particles of combustion during each trial. The MIC utilizes the ionization principle with air drawn through the chamber at a rate of 25 ±5 liters per minute by a regulated vacuum pump.
B1.3 A typical test chamber consists of the following items. When other chamber configurations are used they shall provide a homogeneous smoke/aerosol mix and a laminar air flow across the smoke alarm, adjustable from 0.16 to 0.76 m/s [30 to 150 feet per minute (fpm)].
a) Outer Cabinet – Constructed of 19.1-mm (3/4-in.) exterior grade plywood, and having overall inside dimensions of 1.67 m (65-3/4 in.) length by 464 mm (18-1/4 in.) depth by 460 mm (18-1/8 in.) width. Has a centrally located gasketed hinged top door 860 mm (33-7/8 in.) wide in the top with a 368 by 610-mm (14-1/2 by 24-in.) clear plastic window. A 6.4-mm (1/4-in.) diameter hole is located in the window center for air flow measurement. Box is provided with a 178-mm
(7-in.) diameter exhaust port in the right end, centered 114 mm (4-1/2 in.) above the bottom and employed with a sliding or hinged wooden cover.
b) Inner Compartment – Constructed of 19.1-mm (3/4-in.) plywood, having inside dimensions of 1.06 m (41-3/4 in.) length by 292 mm (11-1/2 in.) height covering the entire width of the inside of the outer cabinet. The left end has a 102-mm (4-in.) diameter hole for the 30 – 35 fpm circulating fan centered 114 mm (4-1/2 in.) from the side and 98 mm (3-7/8 in.) from the bottom rear corner, a 146-mm (5-3/4-in.) diameter hole for the 150 fpm circulating fan centered 96.1 mm (3-7/8 in.) above the bottom, and a 102-mm (4-in.) diameter hole for the light beam centered 76.2 mm (3 in.) in either direction from the top back corner. The right end is the same as the left end except that it has one additional 102-mm (4-in.) diameter hole centered 76.2 mm (3 in.) in either direction from the top front corner. Nominal 15.9-mm (5/8-in.) molding strips are used to secure the end pieces and the top. All interior surfaces are painted with a flat black paint.
c) Circulating Fan 91 mpm (300 fpm)c – sized sufficient to obtain 91 mpm (300 fpm). The fan, located on either side of the opening, is connected to a motor controller (autotransformer) or equivalent to adjust speed.
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l key components：
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UL 217/UL 268 smoke box
include：
wooden box, fans，Lamp，photocell，wick holder
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1 sets
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NI DAQ system
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1 sets
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Smoke box test system
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1 licence
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wicks(about 90m）
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1 pcs
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DC power supply (keysight)
25V,1A，6V,1A
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1set
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PC
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1set
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Delta MIC
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Order seperately
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