Firing variables and strain sensitivity of Bi2Ru2O7 thick resistive films

Abstract

In order to provide accurate and semi-real-time information about performances and conditions of various civil engineering structures thick-film resistors are often being used as strain sensors. For that purpose, Ba2Ru2O7 thick resistive films based on compositions with sheet resistivities of 1 kOhm/sq, 10 kOhm/sq and 100 kOhm/sq were evaluated. Resistors were fired at three different peak temperatures (825oC, 850oC and 875oC) and with three different dwelling times (5 min, 10 min and 15 min) in order to correlate influence of firing variables and thick resistive film strain sensitivity by tracking structure-related changes in resistance, gage factor and noise index values. For 10 kOhm/sq composition values of resistance change vs. temperature and temperature coefficient of resistance were measured and calculated.