Emissivity of Wire Insulation

I've noticed that emissivity heavily affects the temperature readings of a wire (outter surface of insulation). Anyone know the emissivity of this insulation? Any suggestions when reporting temperature readings of electrical equipment?

I recommend you to take Level 1 course of Infrared Thermograhy!

Jesse,

The emissivity or most cable insulation is going to be relatively high, but the precise value is dependent upon a number of factors such as the waveband sensitivity of your imager, the temperature of the wire as well as what type of cable you're inspecting.  There are numerous different types of cable out there and the insulation materials can and do differ from type to type.  If you're inspecting 600VAC class equipment, much of the cable you're seeing is probably insulated with a PVC type material.  THHN, THW-2, MTW and several other types are insulated with PVC.  THWN-2 is PVC with a nylon outer jacket.  When you get into medium voltage cables, the insulating material changes, cross-linked polyethylene is pretty common, and it essentially qualifies as a type of rubber.

PVC is generally expected to exhibit an emissivity of somewhere between .90 and ,95 in the longwave spectrum, so somewhere in that general range is where you could expect the emissivity of wire insulation to fall, assuming you're inspecting a PVC coated wire type.

I hope I've helped.

Ah, makes sense. Thanks for your help!