The Berlin emissivity database is a spectral library providing a basis for the interpretation of thermal emission spectra of planetary regoliths. It contains spectra of plagioclase and potassium feldspars, low and high Ca pyroxenes, olivine, sulfur, Martian analogs, and a lunar highland sample in the wavelength range 3–50 μm. Four particle sizes with dimensions , 25–63, 63–125, 125–250 μm are measured for each sample. An exhaustive suite of tests was implemented, to characterize the setup in the planetary emissivity laboratory and the emissivities collected in the spectral library. The tests improve the quality of measurements, optimizing the sample preparation, calibration algorithm, sample, blackbody, and chamber temperatures, and all the parameters entering in the measurements or calibration processes. The results of our tests are shown and discussed, together with the implications that these results have on the development of the measurement and calibration procedures.