A system for measuring thermal degradation of composites, may include a housing having an interior with an opening shaped to expose a test area of the composite to be tested to the interior; a light-emitting diode that emits primarily ultraviolet radiation, the diode mounted on the housing to direct the ultraviolet radiation into the interior and through the opening; an image sensor mounted on the housing and open to the interior to receive radiation emitted from the test area passing through the opening into the interior; and an image processor connected to receive a signal from the image sensor, the image processor determining a presence or absence of thermal degradation of the test area in response to the signal.