This paper presents design and testing a reference grey body fabricated using different-depth microcavities. The apparent emissivity is achieved by varying the shape coefficient K defined as depth/width ratio. Three different values of shape factor were used in the measurements, K=1.6, 4, 9. There are 2 versions of the emitter made of aluminium and copper, with different coatings made of titanium and nickel. Beneath the emissive surface, a Peltier cooler/heater is located with a closed loop

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... erature regulation system. The proposed emitter allows changing the emissivity sharply, and therefore can be applied everywhere the simultaneous measurement of different infrared radiation levels is required. It is dedicated for testing and calibrating modern observations and fully calibrated IR systems. The paper presents the radiation heat transfer analysis of the emitter based on configuration factors. The numerical, analytical and measurement results are compared.