Principle and Applications of Magnetic Grating Encoders

This article introduces a sensor for measuring rotational or linear displacement—the magnetic grating encoder. Its working principle is based on magnetic pattern changes on the grating to measure displacement or angle. Here we explain the encoder’s principles and typical applications.

1. Principle

A magnetic grating encoder consists of a magnetic grating strip and a read head. The grating strip has many parallel magnetic bands with fixed width and spacing. When mounted on a rotating shaft or moving device, the strip rotates or moves. The read head has magnetic sensors that detect field changes as the strip moves. By measuring these changes, the read head calculates angle or displacement.

2. Advantages

1. High resolution: can measure very small displacements and angular changes with high accuracy.
2. High speed: fast response suitable for high-speed rotation and linear motion.
3. High precision: magnetic measurement yields stable results unaffected by mechanical wear.

3. Applications

Magnetic grating encoders are widely used in robots, automation systems, automotive, aerospace, medical devices, etc., mainly for precise positioning and motion control. As technology advances, their applications will continue to grow.