Hot-Wire Coil Ignitability Test Apparatus
Product details: Model ZLT-HWI
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.
Standard Outfit:
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 mm3, black interior,
Power supply: 220V50Hz other voltages request.