Upgrade of high accuracy hybrid DC temperature bridge for interferometric length measurements

A mix of modern automated, non-invasive minimum-changing approaches was designed to improve temperature measurement speed and metrological reliability for interferometric measurements using good performance old temperature bridge system, which was based on clever combination of hybrid thermocouple plus platinum resistance measurements, good overall electrical stability, and periodic verifications. A Labview application was developed to accurate, continuous and simultaneous time acquisition of voltage signals at different sensors and system points through a multi-channel interfaceable multimeter, maintaining original features. That allows cross validation of both systems with best length calibration uncertainties and calibration practices using fixed points cells as temperature primary references.