Encoders that measure absolute position magnetically rather than optically come from Turck, Minneapolis.
The Kubler 3650 and 3670 encoder Series give a resolution of 9 bits with SSI, 4-to-20 mA, or 0-to-10-Vdc output. The encoders have an IP69K protection rating and temperature range of –40 to 85˚C so they can work outdoors. Their die-cast housings are said to resist shock (>500 g) and vibration (>30 g).
A compact design and blind hollow shaft of up to 10-mm diameter lets the encoders mount in tight spaces and on a tight radius, even with large shafts. Additionally, the magnets can be configured for a suitable measuring range (45˚, 90˚, 180˚ or 360˚) as needed. Integrated LEDs for reference point detection simplify startup and fault diagnostics during maintenance.