Measuring simultaneously position, acceleration, speed and temperature


The new Twiist multivariable position transducer from Gefran has a particularly compact steel case that, in a diameter of 16 mm, encloses the technological heart of the sensor, a patented system for measuring position based on the 3-dimensional Hall Effect. Twiist is capable of simultaneously measuring position, linear acceleration, angular velocity, and sensor temperature. It also implements virtual speed and inclination sensors based on a summary of position and acceleration measurements. Thanks to its water resistance and shock and vibration absorption, Twiist is the ideal solution for measuring position in various industrial sectors and in mobile hydraulics.

Twiist is an example of a smart sensor: thanks to its powerful integrated CPU it is in fact able to analyse and correlate the data collected in order to ensure monitoring and analysing the processes and machines to which it is applied. TWIIST supports the development of application-specific proprietary algorithms, which open up completely new horizons in the world of sensors.

Thanks to IO-Link (LM-L model) and CANopen (LM-C model) digital outputs, measurements relating to process variables, such as position and speed or angle of inclination, are transmitted digitally for up to 1,000 times per second. At the same time, the sensor is capable of processing and making available acyclic information such as vibration peaks, maximum temperature reached, hours of work, and number of km travelled by the cursor, useful for analysing and further understanding the machine behaviour. It is possible to calculate and transmit additional acyclic variables depending on the proprietary algorithms implemented.

Another new feature is the possibility of updating the firmware via bus, thanks to a Boot Loader that ensures updates directly on site. For customers, this feature translates into a sensor that is always up-to-date and that may be expanded with new functions over time.

“Twiist is a transducer that will revolutionise the very concept of measurement”, said Davide Alghisi, Innovation Manager and Head of R&D Linear Sensors at Gefran. “TWIIST goes beyond the aggregation of multiple primary measurement elements within a single device: the interaction between real and virtual sensors and the ability to correlate the evolution of measurements over time is an absolute novelty. Depending on the specific customer applications, it is possible to enable unprecedented self-diagnosis, self-correction, and machine and process behaviour detection features, including predictive maintenance”.

The whole range is available in strokes (FS) from 50 to 900 mm, has a typical linearity of 0.15% FS and typical repeatability of 0.05% FS, and is capable of operating in a temperature range going from -40 to +85°C. Several mechanical connections to the process are available, including self-aligning joints for maximum ease of installation. The range is completed by the LS-A versions with mono-variable analogue output (current, voltage or ratiometric), as well as the redundant ratiometric version to support safety applications.