Characterisation and development of novel thick film strain gauges
The strain gauge is a physical sensor, in which the influence of an externally applied strain causes the resistance to undergo a reversible change. It can be applied to the measurement of force, pressure, and displacement etc. The thick film strain gauge is relatively new however and has been seen to have many advantages. System zero (offset) and system gain (sensitivity) are key characteristics of the strain gauges. Hence intensive research was carried out to study these two aspects of different construction types of thick film strain gauges, i.e. X-plane and Z-plane strain gauges. Different fabrication parameters of these devices were studied for their effect on the characteristic. Temperature characteristics of both of these types of devices were examined as a measure of system zero stability. Combinations of resistor thickness, construction materials and geometric parameters of these types of devices were noticed to affect their temperature behavior. These observations would undoubtedly facilitate the achievement of good TCR matching between resistors in practical application. A programme of explanatory theory to understand these observations has been submitted, which comprises strain analysis and conduction mechanism study. Loading characteristics of Z-plane strain gauges have also been studied to explore the potential of this type of device.