Abstract: This study examines the new techniques and instruments used in the measurement of thermal emissivity over the past two decades. Some of them have been evaluated with full details based on similar functions while others are not. Some devices utilize interferential filters to perform the spectral measurements which happens to be the simplest method to isolate a spectral range while others utilize spectrographs or monochromators that choose a narrower wave band compared to the filters. Lastly, others utilize the Fourier Transform Infrared (FTIR) spectrometer that measures the entire spectral range under study in each method of measurement and maximizes the ratio of signal to noise. Studying these devices with similar features can lead to building a better device that optimizes all the advantages from these other devices.