An investigation of thick-film resistor, fired at different temperatures, for strain sensors

Some commercial 10 k/spl Omega//sq. thick-film resistors based on RuO/sub 2/, ruthenates or a mixture of RuO/sub 2/ and ruthenates, were evaluated for strain gauge applications. The resistors were fired at different temperatures to determine the influence of firing temperature on the electrical characteristics. The conductive phase in the resistors was determined with X-ray powder-diffraction (XRD) analysis. Microstructures of the thick-film resistors were analysed via SEM and EDS. The temperature coefficients of resistivity, noise indices and gauge factors (GFs) were measured. The results indicate that both the GFs and the noise indices are different for resistors with the same nominal sheet resistivity but which came from different resistor series.