Multiturn sensors which utilise the GMR Effect (Giant Magnetoresistance) yield absolute positional values, do not require any type of reference signals, and need neither power supply nor buffer battery for rotational sensing. They are typically used in so-called True Power On-Systems for a wide variety of industrial applications. And now, the range of applications is likely to expand:
Novotechnik has advanced the GMR sensor technology and is now offering the Multiturn sensors of its RSM 2800 series equipped with digital interfaces. The measuring range is 14 or 16 revolutions; measurements are output as SPI or SSI signals. A version with CANopen interface will be available soon. These robust sensors, with their small footprint and tiny diameter of only 28mm, are designed for total resolutions in the range of 16 to 18 bits (14 bits for angular sensing, and 1 to 4 bits for revolution counts). And with linearity deviations of +/-0.036 per cent over the entire measuring range, their accuracy is impressive as well.
The robust sensors of this series are designed to comply with protection requirements of up to IP67 and are therefore protected against dust and temporary submersion. They can easily be integrated into the desired applications. The shaft design permits easy take-up with angular-indexing by a customer-supplied counterpart. Typical applications include mobile machinery, actuators, or hydraulic lifts, as well as robotics. Generally, they are utilised as alternatives to multiturn potentiometers and encoders.
For further information about these multiturn sensors, please visit www.variohm.com.