Torque sensor with separate sensing head can probe deep into machinery

Sensor Technology extends its new range of torque sensors with a model that offers the sensing head and electronics in separate housings. This has two advantages: the sensing head can fit into extremely confined spaces, and the electronics can be located in a place where they are shielded from physical damage, dust, dirt, moisture, electromagnetic forces, etc.

The new TorqSense SGR530/540 series functions on the same principle as all the other SGR510/520 units, with a full four-element strain gauge bridge. This utilises four individual strain gauges fastened to the drive shaft; each measures the deflection of the shaft in a different direction as it rotates under load. The electronics gather readings from all four gauges and calculates the torque value.

"Because of our experience with the RWT, we have been able to compress the development times for the new SGR models considerably," says Sensor Technology's Mark Ingham. "So, we have been able to react to specific enquiries from individual users and bring forward model launches."

The new range satisfies emerging user necessities, notably accurately recording transient torque spikes. Transducers did not have the bandwidth to capture these spikes in the past, so they were ignored. However, advances in automation, continuous operation and the growing demand for accurate track and trace data has led to the requirement for more detailed measurement and analysis, as Mark explains:

"A single spike could indicate, say, the wrong amount of an ingredient being added to a compound or an oversized workpiece, both of which could affect product quality. A series of spikes would probably suggest the beginnings of a problem within the machinery, so their detection gives the plant engineers an early warning".

Other advantages of the range include eradicating noise pickup and signal corruption associated with slip rings and hard-wired solutions, a 400% mechanical overload limit with accurate torque measurement even at these extremes, and multipoint calibration to eradicate linearity errors within the sensor.

All units are accurate to +/-0.1% and resolution to +/-0.01% of the transducer's full scale. Other features comprise an adjustable moving average filter, power supply range from 12VDC to 32VDC, user-settable analogue output voltages, and RS232, USB, CANbus and Ethernet comms options.

"Like the RWT sensors, the new SGRs can integrate digitally with TorqView software and LabView virtual instruments," says Mark.