Title screen

Transducers of current to voltage, such as current shunts are widely used in control systems for the mechanical engineering. The shunt is required to determine the value of its resistance on DC and AC currents to determine the transfer ratio error in the wide frequency band in process of verification or calibration. Well-known methods for resistance measuring (by Thompson' double bridge; magnetic comparator, compensation technique, etc.) require a commerce resistance and difficult to implement for shunts with resistance less than 0.1 Ohms. The paper describes a procedure for measuring the complex impedance of transfer ratio of current shunts in the frequency band using the lock-in amplifier with the differential input. The experimental results of the proposed procedure for coaxial shunt with nominal resistance at DC 750 uOhm and 160 uOhm are described.