A new emissivity measuring apparatus based on infrared thermal imager

•The method of independent temperature control of three resistance wires is adopted to keep the heating temperature uniform.•The sample stage adopts Hastelloy to maintain good thermal stability.•The allowable rectangular sample size is 80*60 mm, which enables point and surface temperature and emissivity measurements.•The measurement results are displayed by a three-dimensional image.•Solve the problem that blackbody traditionally needs to be calibrated every time when material emissivity is measured.