Characterisation of a thin-film/thick-film strain gauge sensor on stainless steel

Abstract Thin-film strain gauges of the mixed oxide Bi 2 O 3 -V 2 O 5 have been deposited on insulated stainless steel substrates. The thin-film gauges are insulated from the steel by application of dielectric layers printed using thick-film techniques. Various strain gauge parameters are analysed, including linearity, hysteresis, repeatability and temperature effects. Comparisons have also been made with similar gauges deposited on glass. It has been observed that the thin-film strain sensor deposited on steel performs much better than the one deposited on glass in terms of maximum applicable strain, hysteresis and linearity. However, the film on glass is much more sensitive than the one deposited on steel. The lower-sensitivity of the sensor on steel is attributed to the increased thickness of the deposited resistor and the poorer surface characteristics of the thick-film dielectric layers. The d.c. conductivity variation at high temperatures has also been studied and it has been observed that freeband conduction takes place at these temperatures.