technical note: Strain gauge slip ring circuits

This note describes practical uses of high quality slip rings for strain gauge measurements on rotating machinery. The advantages and disadvantages of various circuits are discussed and recommendations made for the best performance. Consideration is given to the most efficient use of the number of slip rings in a given system for the maximum data which can be obtained avoiding errors caused by slip ring noise. Other parameters which are considered are: the voltage applied to the bridge; the number of rings used to deliver power to the strain gauges and the gauge resistance. Some practical information on slip ring noise, life and cross talk and how to reduce it in the Chevron Bridge Circuit is also discussed.