Product details: Model ZLT-HWI
Hot wire coil ignitability test apparatus,to measure the time required to ignite the test specimen during the application of heat from an electrically heated coil as an ignition source, according to IEC60695-2-20.
A rectangular bar-shaped test specimen is supported horizontally at both ends, the centre portion is wrapped with a coil of heater wire, a fixed power density is applied to the coil, which rapidly heats up and the behavior of the test specimen is observed. The time to ignition is recorded and/ or a melt through condition is recorded as M.
This test method assesses the relative resistance of electrical insulating materials to ignition by the effects of a hot wire.
1 current, current yielding a linear power density of 0,26W/mm±0,01W/mm through the heater wire,
1 test specimen winding device, according to IEC60695-2-20 Fig 4, shall be provided to wind five turns of the heater wire uniformly on the test specimen with a 6,3 mm±0,2 mm pitch and a tension of 5,4 N±0,05 N,
1 test fixture, two supporting posts, positioned 70 mm±2 mm apart are provided with hold down clamps to support the test specimen in a horizontal and flat position. The test specimen shall be supported 60 mm±2 mm above and in the approximate centre of the bottom of the chamber,
1 supply circuit, provided 0,31 W/mm power density, adjusting the power level smoothly and continuously, with an on-off switch for the test power and timers to record the duration of application of the test power,
20 m NiCr (80/20) heater wire, having a diameter of 0,5 mm+0,020mm, and has a nominal cold resistance of approximately 5,25Ω/m
1 chamber with a volume of at least 0,5 m3, black interior,
Power supply: 220V50Hz other voltages request.