Given that partial discharges are generally hotter than their surrounding media (see
earlier), it might reasonably be thought that the thermal imaging camera could be
applied in their detection and measurement. Unfortunately, most partial discharges
are enclosed in some way, e.g. within solid insulation or within metal clad enclosures.
Given the relatively low temperatures of partial discharges and the high thermal
impedances likely to be present between such discharges and the imaging camera, its
use is very limited in this application.