True-twin microcalorimeter: proof-of-concept experiment

Presented is a proof-of-concept experiment to realise the microwave primary power standard with a true-twin microcalorimeter. Double feeding line microcalorimeters are widely used by national metrology institutes. A drawback concerns the system calibration: traditional processes change measurement conditions between system characterisation and the measurement stage. Nevertheless, if the feeding lines are made twin, a measurement scheme that avoids separate characterisation can be applied, equations simplified and time consumption is halved. Here the feasibility of the idea is demonstrated. The result of an effective efficiency spectroscopy of a thermoelectric power sensor is compared with figures obtained with well-established methods.