Abstract
Precision bridges and potentiometers developed recently for resistance thermometry are reviewed with emphasis on the principles of their operation. Direct current apparatus discussed include potentiometers of the Lindek type and flux-coupled direct current comparator, both capable of resolution at nanovolt level. Amplifier-null detectors are also discussed. Different types of alternating current bridges are described. They differ in the principle on which the transformers work. Advantage of self-balancing AC bridges in an automatic calorimeter controlled by a microcomputer is shown with an example of noise reduction by averaging.
