Patent ID: 8838404

Claim:
A physical quantity sensor, comprising: a physical quantity detecting element that detects a physical quantity of an object to be measured; a temperature detecting element that detects a temperature of the physical quantity detecting element; a correcting equation storing portion that stores correcting equations including a first correcting equation and a second correcting equation, and two sets of information as information for the correcting equations used in a correction process to eliminate a portion of fluctuation due to temperature variation from a detection signal of the physical quantity detecting element, the two sets of information including, respectively, first information for the first correcting equation that is applied when the temperature of the physical quantity detecting element is included in a first temperature range, and second information for the second correcting equation that is applied when the temperature of the physical quantity detecting element is included in a second temperature range that does not overlap the first temperature range; a temperature range determining portion that determines a first temperature range or a second temperature range as a temperature range wherein the temperature detected for the temperature detecting element is included; and a correction calculating portion that uses the correcting equation corresponding to the temperature range determined by the temperature range determining portion to perform temperature correction to correct the detection signal by the physical quantity detecting element and outputs the post-correction signal as a measurement signal, wherein the first correcting equation and the second correcting equation are linear equations that minimize the maximum difference between an output value corresponding to the detection signal of the physical quantity detecting element and a value corresponding to the measurement signal after correction, in the respective temperature range pertaining to that correcting equation, and the correcting equation storing portion further stores additional two sets of information as information for the correcting equations used in a correction process to perform pressure correction after the temperature correction, the additional two sets of information including, respectively, third information that is used for performing the pressure correction after the temperature correction when the temperature of the physical quantity detecting element is included in the first temperature range, and forth information that is used for performing the pressure correction after the temperature correction when the temperature of the physical quantity detecting element is included in a second temperature range that does not overlap the first temperature range.