Thermal management is critical to heatsink performance which can be tested with Thermex temperature distribution film from Sensor Products. The economical, thin sensor film can be used as a design and assembly quality control check in virtually any application, claims the company, to test and monitor heated contacting surfaces from 93 to 149°C. Upon exposure to heat and contact, the sensor film changes colour in 0.1s, or less, to permanently reveal relative temperature distribution between any two surfaces. The intensity of this colour change directly relates to the temperature it was exposed to enabling the film to reveal spot high or low temperature zones and minute surface variations. The film can be used in invasive, intolerant environments and interfaces that are not easily accessed with traditional temperature indicators and infra red thermometers. The film that has been used for testing may be saved for archival purposes but, the company claims that its low cost renders it disposable when this is not necessary without a financial penalty. A sheet can be easily trimmed for smaller applications or custom cut to defined dimensions. Post processing analysis is also available for temperature fluctuations that need to be analysed with great precision, says the company.