Simulator for Bridge Measurements

The arrangement of resistors shown here can be used to test bridge amplifiers with differential inputs. Such amplifiers are used in conjunction with strain gauges, for example, or in measuring inductances or capacitances. Because of their symmetrical construction, bridges allow the tiniest variations in the quantity in question (for example, resistance) to be amplified without resorting to complex compensation techniques.
The circuit here simulates small variations in one of the resistors that forms the bridge, as happens in the example of strain gauges. Since only standard metal film resistors are used, it is suitable only for general testing of the connected amplifier.