Radiation device with variable degree of polarisation includes infrared radiation source, polarisation degree control device and variable temperature unit arranged in series on optical axis. The infrared radiation source is made in the form of a massive hemisphere of homogeneous material and performs the function of a polarization degree control device, and the variable temperature unit includes a heater located in the center of the hemisphere and temperature sensors located along the perimeter of the hemisphere base.

The useful model relates to the field of instrument making, in particular to measuring equipment for monitoring the initial characteristics of optoelectronic observation systems, namely to means for calibrating polarization thermal imagers.