Strain gage bridge circuit with sensitivity equalization and method for sensitivity equalization

Abstract

A strain gage bridge circuit and method for sensitivity equalization, particularly suitable for load cell devices for precision measurement. The sensitivity of opposing half-bridges in a strain gage bridge circuit is equalized by a pair of equal, fixed resistors connected across a bridge diagonal formed by the two half-bridges, and a third resistor connecting the junction of the two equal, fixed resistors to the center of the half-bridge with the highest sensitivity. The effective shunting of the most sensitive half bridge can be changed by changing the value of the third resistor, while the ratio of the two equivalent shunting resistance values remain exactly constant. The total load on the bridge diagonal also remains constant when the value of the third resistor is changed. Both sets of orthogonally arranged opposed half-bridges in a strain gage bridge circuit can be equalized independently when two sets of equalizing resistors are used.

Dependencies are inferred from the claim text.