A sensor circuit is provided that includes at least one pair of
interconnected T-networks. Each pair has a first T-network including a
first impedance serially connected to second impedance at a first
junction and a first variable resistance sensor element connected to the
first junction. Each pair also has a second T-network including a third
impedance serially connected to a fourth impedance at a second junction
and a second variable resistance sensor element connected to the second
junction. The sensor circuit further includes an operational amplifier
connected to the first T-network of a selected one of the at least one
pair of T-networks and a constant voltage source connected to the second
T-network of the selected T-network pair.