Monitoring heatsink performance, Thermex thin temperature sensor film is viable for testing and monitoring surface temperatures from 200°F to 300°F. Useable alone or with Fuji Prescale pressure indicating film, Thermex changes color instantaneously and permanently upon exposure to heat to reveal temperature distribution between any two contacting surfaces. Intensity of color change directly relates to temperature variation, enabling the film to reveal spot high or low temperature zones and tiny surface variations. SENSOR PRODUCTS INC., Madison, NJ. (800) 755-2201.