Abstract:The measurement accuracy of silicon piezoresistive pressure sensor is subject to the influence of temperature drift, nonlinear error and etc., existing measurement error numerical compensation methods have low realtime performance. A stepbystepdifferent frequency compensation method basedon twoelement interpolationis proposed. The methodisimplemented asfollows: firstly,the cubic splineinterpolation algorithmis usedto interpolatethe outputvoltage andworkingtemperature ofthe sensor, and suppresstemperaturedrift;andthen, Lagrange interpolation algorithm is used to interpolate the pressure and voltage piecewisely, and reduce the nonlinear error; meanwhile, the frequency of the temperature interpolation is decreased to reduce the calculation burden in each pressure interpolation period, and overcome the shortcoming that traditional interpolation compensation method calculates two variables in one interpolation period and the calculation is timeconsuming. Experiments on sensor calibration and error compensation were conducted, the results verify that the compensation accuracy meets the error requirement of ± 005% FS in the temperature range of 0～60℃, and the data output rate of 1 kHz is achieved in the designed acquisition system; the experiment results indicate that the proposed method can effectively improve the measurement accuracy of silicon piezoresistive pressure sensor, has good real time performance and can realize error online compensation. The proposed method possesses a certain engineering value in the gas pressure measurement in aeroengine tests.