Which sensor measures acceleration along three axes?

• A. 3-axis gyroscope
• B. Tilt sensor
• C. Magnetometer
• D. 3-axis accelerometer

Answer: (D)

Measuring acceleration along three axes requires a sensor designed to sense linear acceleration in the X, Y, and Z directions. A three-axis accelerometer does exactly that, often using MEMS technology to detect changes in velocity per second along each axis, typically expressed in g’s. This is essential for detecting motion, vibration, and changes in orientation when used as part of an IMU. The other options don’t fit: a gyroscope measures angular velocity (rotation) rather than linear acceleration; a tilt sensor provides orientation relative to gravity but usually not full three-axis dynamic acceleration; a magnetometer measures magnetic fields, not acceleration. So the three-axis accelerometer is the correct choice.