Development of a capacitive mass measuring system

The paper deals with the theory, design, fabrication and test results of a robust, linear and accurate capacitive mass sensor. The change in capacitance, with increased mass, takes place due to the shielding effect of a conducting cylinder which moves in between the stationary concentric co-axial cylinders. A direct capacitance measuring system, developed by the authors, is used in the calibration of the mass sensor. Presented sensor is linear, immune to temperature errors, highly flexible in the design and can cover different weighing ranges by selecting proper springs only. For the spring, used in the system, mass sensor can weigh up to 4 kg.