Hotwire Ignition Tester
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 center 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 center 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.