Performance of thick film strain gauges at cryogenic temperatures

Thick film resistors have been prepared on enamelled steel substrates and their extensometric properties have been investigated at 300, 77 and 4.2 K. The measurements made included the longitudinal and transverse gauge factors, the temperature coefficients of resistance and of the gauge factor, and current noise. Repeatability and apparent strain have also been evaluated. The characteristics of strain gauges prepared from two different resistive systems, based on RuO₂ and ruthenate particles, respectively, have been compared. The results show that thick film resistors on enamelled steel are adequate for the development of sensors and transducers of strain and strain-related physical quantities in cryogenic environments.