1. A system for determining a conductance of an object, the system comprising: a sensor configured to emit an electromagnetic field when an excitation signal is received, wherein the electromagnetic field interacts with the object when the object is positioned within the electromagnetic field; a signal processing circuit coupled to the sensor and configured to: provide an adjustable capacitance to the sensor to adjust a phase angle of a current flowing through the sensor; generate a voltage measurement representative of a voltage across the sensor; and generate a current measurement representative of the current flowing through the sensor; and a controller coupled to the signal processing circuit, the controller configured to: calculate an admittance of the sensor based on the voltage measurement and the current measurement; and determine a conductance of the object based on the calculated admittance of the sensor.