Coaxial and waveguide microcalorimeters for RF and microwave power standards

Four sets of coaxial and waveguide microcalorimeters for measuring the effective efficiency of bolometer mounts are described. The systematic uncertainties due to the RF loss in the thermal isolation section, the loss in the wall of the mount, and the nonlinear thermopile response are discussed. The results of measurements and intercomparisons are presented.<
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