LAUSR

This work aims to achieve contactless absolute-temperature measurements of infrared-semi-transparent solids using an infrared thermal and spectroscopic imaging technique. The multispectral thermo-transmittance coefficient fields in the 3–5 μm wavelength range for Sapphire, KBr, and Silicon are determined to be 6 × 10−4 K−1, 4 × 10−4 K−1, and −3 × 10−3 K−1, respectively. The most interesting result is the high temperature-dependent transmittance coefficient in the middle wave infrared region. With these coefficients, the absolute temperature fields in a range from room temperature to 140 °C are shown.