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A study was initiated to determine the feasibility of employing attenuated total reflectance Fourier transform–infrared spectroscopy (ATR/FT–IR) to detect changes resulting from thermal ageing in the enamel of copper magnet wire. Polyamideimide (SX-81002) was cured on a zinc selenide (ZnSe) internal reflection element (IRE) coated with a thin film of metallic copper. The coated IRE was inserted in a Circle cell housed in a heating jacket and maintained at 250°C on the optical bench of an infrared spectrometer to simulate thermal ageing of enamel-coated magnet wire. Evaluation of the infrared spectra in the fingerprint region suggested that the polymer experienced chemical degradation within a 23 day period of thermal ageing. Through comparisons with controls containing no copper coatings, and ageing studies carried out at 28°C, it was determined that ageing at elevated temperature caused more pronounced chemical changes in the polymer than did exposure to the copper. These results indicate that ATR/FT–IR may be a useful tool to detect enamel fatigue after a short period of thermal ageing.