Constant-flow static resistance strain gauge

The utility model relates to a constant current type static resistance strain gauge, arranges a constant current source and an electrical analog switch circuit on the input end of the bridge circuit, adopts the switching technique of the constant current stimulating the electron switch, and thoroughly overcomes the abuse of the existing strain gauge using the hand switch and the relay contact to carry out the bridge circuit switching. The utility model excludes the resistance of the electrical analog switch circuit out of the bridge circuit testing the change of the resistance. Thus, the output voltage of the strain gauge is related with the drive current, the strain resistance, the strain gage sensitivity coefficient and the strain value, has no relationship with the wire resistance, and also has no relationship with the electrical analog switch resistance. Simultaneously, the utility model has no bridge circuit non-linearity for large strain measurement. The utility model has small volume, light weight, strong interference rejection, and good stability, is an excellent substitution commodity of the present constant-voltage type static resistance strain gauge, is adapted for the structural stress measuring of many fields of machinery, civil engineering, etc, and is one of the important instrument of the scientific research and teaching.