Accelerometers are sensors that measure acceleration, detecting changes in velocity as an object moves or experiences shock. They are widely used in automotive safety systems, smartphones, health monitoring devices, aerospace, and robotics to monitor and analyze the motion state of objects.

What is an Accelerometer?

An accelerometer is a device that measures the vibration or acceleration of motion within a structure. When vibrations or changes in motion occur, the resulting force causes a mass to compress the piezoelectric material, generating an electrical charge that corresponds to the force applied. Since this charge is proportional to the force and the mass remains constant, it also correlates with acceleration. These sensors are widely used in various applications—from space stations to handheld devices—and you likely own at least one device with an accelerometer, such as a smartphone. In smartphones, accelerometers detect acceleration in any direction, enabling features like the automatic rotation of the display when you turn the phone. In industrial environments, accelerometers assist engineers in assessing machine stability and monitoring for any undesirable forces or vibrations.

How does an accelerometer work?

An accelerometer functions through an electromechanical sensor specifically designed to measure both static and dynamic acceleration. Static acceleration refers to constant forces acting on an object, such as gravity or friction, which are largely predictable and uniform. For instance, the acceleration due to gravity remains constant at approximately 9.8 m/s² and is nearly the same at all locations on Earth.

In contrast, dynamic acceleration involves non-uniform forces, with vibration or shock being prime examples. A car crash illustrates dynamic acceleration well, as the change in acceleration is abrupt compared to the vehicle's previous state. The principle behind accelerometers is their ability to detect acceleration and convert it into measurable quantities, such as electrical signals.