Comparison of Experimental Techniques for Evaluating the Correction Factor of a Rectangular Waveguide Microcalorimeter

We evaluated the correction factor of a new WR-15 (50-75 GHz) rectangular waveguide microcalorimeter with four different techniques. The four methods are in agreement. The technique with the lowest uncertainty utilized two identical microcalorimeter core sections whose reference planes were connected to each other. Use of this technique has enabled us to reduce the uncertainty in effective efficiency by a factor of 2.5 relative to an earlier microcalorimeter.