I agree with JT. The old -141 uses Systron-Donner (Helium pressure) on the engines/pylons, and Kiddie inconnel (resistance) on the wings/apu. To add to what he said about the SD, it has a pinpoint and overall heat setting.
Pylon avg 400F, discreet 950F
Fwd Cowl avg 350F, discreet 1050F
Aft Cowl avg 500F, discreet 1050F
The inconells are 195/205 C for the anti-ice, 310 F wing bleed air, and 232 C Apu, both of which only have one indication, either "on" or off".
This isn't the 747, but the principle is the same.
"Never trust a clean Crew Chief"