DESIGN OF A LOW-TEMPERATURE BLACKBODY RADIATION RESOURCE WITH A FROST PREVENTION UNIT

摘要

A new type of blackbody radiation resource for providing target temperatures between -80°C and + 100°C is presented. The blackbody adopts a stirred fluid bath to achieve temperature uniformity along the cavity and uses nitrogen gas to flush the cavity. The temperature of nitrogen gas is the same as that of the bath because the gas is heat exchanged with the working fluid in the bath. In this way, the designed blackbody can prevent air condensation on the wall and the window of the cavity when operated at temperatures below dew point, and furthermore the temperature distribution along with the wall is uniform. The calculated and measured emissivity of the designed blackbody cavity is large than 0.997.