Drives and Controls Magazine

Contactless encoder will work in the wet

01 September, 2001

Contactless encoder will work in the wet

Siko has developed a contactless encoder system that it claims will operate even when immersed in fluids. The Roto system consists of a magnetic ring with distance information encoded on its circumference, and a sensor which reads this information and converts it to standard quadrature incremental signals.

The magnetic ring is fitted directly onto a rotating shaft, with the sensor mounted nearby so that when either part rotates, signals are generated. The system is said to be unaffected by vibrations or shocks.

The system can operate at circumferential speeds of up to 25m/s and can produce resolutions of up to 20,000 pulses per revolution, with a repeat accuracy of ±1 increment. This corresponds to an angular resolution of 0.0045 degrees and a 0.1 degree system accuracy.