US Patent 7646190 Stress measurement device and stress measurement method

A stress measurement device includes a current supply portion; a series circuit which is connected to the current supply portion and has a piezoresistive element that forms a single gauge resistance and a compensating diode that is connected in series to the piezoresistive element; and a voltage measuring portion that measures voltage between both ends of the series circuit. The single gauge resistance has a piezoresistive effect in which a resistance value changes according to applied stress, and a positive temperature characteristic in which the resistance value increases depending on an increase in temperature. The compensating diode is provided in a forward direction with respect to the current supply portion and has a negative temperature characteristic in which a voltage between an anode and a cathode of the compensating diode decreases depending on the increase in temperature.