PCME torque and force transducers are highly robust

Developed by German sensor innovator NTC Engineering with UK and Ireland distribution through Ixthus, the technology is available in a range of standard products or can be integrated directly in performance-critical torque transmission components without the need to make functional design changes. Such components can be submerged in oil or other media at high temperatures.

Employing an effect known as inverse magnetostriction, the sensor determines torque and force at high bandwidths with high accuracy and fine resolution; it works because the magnetic properties of a specially processed ferromagnetic object change in proportion to the mechanical forces acting upon it.

PCME technology comprises three key elements: a primary sensor such as a torque-transmitting shaft that is processed in such a way that an applied force generates a directional magnetic field pattern; a secondary sensor unit that houses the measurement coils; and a signal processing and conditioning module that can be located at a distance from the sensing elements.

These three elements are available as competitively priced integrated torque sensors in standard pillow block and torquemeter designs with optional accuracy grades covering torques up to 3000Nm, shaft speeds to 20,000rpm and bandwidths to 30kHz. Alternatively, Ixthus can provide a complete design service in conjunction with NTC applications engineers to integrate PCME technology directly into customers' components. Due to its low complexity and space-saving features, the price-performance ratio for the complete component can be exceptionally high.

The technology has been successfully applied across a wide range of application areas including motorsports, automotive, aircraft and railways, engine and construction plant, and industrial test and measurement. Specific applications include load pins for shear force measurement on cranes, regulation and speed sensing for electric cycles, torque measurement on high-speed wind turbine couplings, torque regulation on heavy-duty materials processing, and torque measurement for KERS (kinetic energy recovery systems) in Formula 1 motorsports.

As well as the technological benefits of insensitivity to shock and vibration, high-speed data capture and low system complexity, other notable design characteristics of the PCME technology include insensitivity to bending and radial forces, an operational temperature range of -40 to +250degC, low current consumption of only 5mA and long-life, maintenance-free operation with no corrosion and no contacting parts.

In some respects PCME is similar to surface acoustic wave (SAW) technology - such as providing non-contact torque measurement across a wide range of operating conditions - but Ixthus says that PCME is simpler to manufacture and install. Although SAW has slightly superior performance, Ixthus believes that PCME will prove more than adequate for all but the most demanding applications.

Contact Ixthus for more information about Pulsed Current Modulated Encoding (PCME).