Abstract:The real-time measurement of oil rig torque is very important to ensure the safety of work and improve the economic efficiency. In order to solve the problem that the accuracy of strain torque dynamometer is reduced after a period of time, a piezoelectric torque dynamometer is designed, which has a small size, large range and good stability, etc. Firstly, the 3D model of dynamometer is established, and the measurement principle of dynamometer is discussed, then the relationship between the output voltage and the input charge of the charge amplifying circuit is deduced, the charge transfer core circuit with high input impedance that reaches to 1014Ω is designed, and the concrete implementation scheme of the wireless transmission circuit is given. At last, the static calibration of dynamometer is carried out, the nonlinearity is 1.17% and the repeatability is 0.46%. The performance of the piezoelectric torque dynamometer has reached the requirements of real-time monitoring of drilling torque.