Jawaharlal Nehru Technological University Hyderabad B.Tech II TRANSDUCERS AND INSTRUMENTATION Previous Question Paper (May - 2019 - R13)

Semiconductor strain gauges offer two primary advantages: first, they possess a very high gauge factor, typically ranging from 100 to 200, which is significantly higher than that of metallic foil gauges, resulting in high sensitivity and output signals. Second, they are extremely small in size, allowing for precise measurements in localized areas and high-frequency response applications.

A gyroscope angular velocity sensor, typically implemented as a MEMS (Micro-Electro-Mechanical System) device, operates on the principle of the Coriolis effect. It consists of a vibrating mass or proof mass suspended by springs that is driven into oscillation at a constant frequency.

When the sensor is subjected to an angular velocity (rotation) about an axis perpendicular to the direction of oscillation, the Coriolis force acts on the vibrating mass, causing it to deflect in a direction perpendicular to both the oscillation and the axis of rotation. This displacement is proportional to the angular velocity of the sensor.

The sensor detects this displacement through capacitive sensing, where the change in distance between the moving mass and fixed electrodes results in a change in capacitance. This electrical signal is then processed and converted into an output voltage that is directly proportional to the rate of rotation.