How does a 4-wire sensor differ in operation from a 5-wire resistive sensor?
In 4-wire technology the bottom substrate acts as the Y-axis measurement containing a 5 volt input electrode and a ground electrode. The outer membrane (the X-axis) also contains a 5 volt input electrode and a ground electrode. Since the outer membrane acts as the voltage gradient while the bottom substrate probes the voltage measurement, damage to the conductive coating will affect linearity and accuracy. This damage is caused by the continuous flexing of the membrane which over time will wear the uniform conductive coating layer.
