Contactless encoder takes a bath

The German measurement specialist Siko has developed a contactless encoder system, said to operate even when immersed in a fluid such as the oil bath of a hydraulic pump. The maintenance-free Roto encoder system consist of two main parts: a magnetic ring with distance information encoded around its circumference, which is mounted on the rotating shaft; and a sensor, which reads the information and converts it into standard quadrature incremental output signals.

The IP67 system, which will operate at circumferential speeds of up to 25m/s, is said to immune from shocks and vibrations. Various combinations of magnetic ring and sensor can be used to achieve resolutions of up to 20,000 pulses/rev with repeat accuracies of ±1 increment. If used to measure angles, this equates to a step resolution of 0.0045 degrees and an accuracy of 0.1 degrees.