The temperature dependence of the local mode absorption of CAsat 580 cm−1is reexamined using high‐resolution Fourier transform spectroscopy. A new carbon‐related line is detected at room temperature on the low‐energy side of the main carbon peak at 576.6 cm−1. It follows that the integrated absorption of the whole band is independent of temperature in the temperature range between 77 and 300 K. Calibration factors are given for 77 and 300 K, providing a consistent interpretation of previous data. ©1995 American Institute of Physics.