Access over 120,000 technical material datasheets with Prospector! Créez un compte gratuitement

Hot-Wire Ignition (HWI) - UL 746

Test specimens are wrapped with resistance wire that dissipates a specified level of energy. HWI is the time it takes to either ignite or burn through a specimen.

Performance Level Categories (PLC) were introduced to avoid excessive implied precision and bias.

HWI Mean Ignition Time (sec) PLC
120 and longer 0
60 through 119 1
30 through 59 2
15 through 29 3
7 through 14 4
<7 5