Microcontroller Based Capacitive Mass Measuring System

The paper deals with a new design of a capacitive sensor developed for the accurate and precise measurement of mass. It employs a co-axial cylinder based capacitive sensor whose capacitance decreases linearly with mass, due to the shielding effect of the conducting shield, which moves between the stationary cylinders of the capacitor with the movement of the mass holder. An accurate capacitance to voltage converting system is used to detect the mass in terms of voltage. Linear relationship between mass and output signal is obtained with the help of microcontroller. The presented sensor has high order of linearity, flexibility in design and controllable damping. The overall size of the sensor may be reduced to very small values by this design. It is highly robust and may be attached to any complex system. For the spring, used in the system, mass sensor can measure up to 7 kg.