Remote head torque sensors are accurate to ±0.1%

“This has two advantages,” according to the company. “The sensing head can fit into confined spaces, and the electronics can be located in a position where they are protected from physical damage, dust, dirt, moisture and electromagnetic forces.”

Dubbed SGR530 and SGR540 series, the sensors have a four element strain gauge bridge on the drive shaft along with a microcontroller which spins with them.

Power is supplied over an inductive link, which also carries a digital data stream back to the stator.

“An advantage of the design of the SGR torque sensors is that they automatically compensate for extraneous forces such as bending moments inadvertently applied to the sensor,” said the company.

Bandwidth has been tuned for recording transient torque spikes.

“A single spike could indicate say the wrong amount of an ingredient being added to a compound or an over-sized workpiece, both of which could affect product quality,” said Sensor Technology sales engineer Mark Ingham. “A series of spikes would probably suggest the beginnings of a problem within the machinery.”

All units meet the ±0.1% accuracy, and resolution is ±0.01% of full scale.

• SGR530 transducers have a pair of voltage or current analogue outputs, onw representing torque and the other for speed or power. They also measure shaft temperature, and include self-diagnostics.
• SGR540 transducers have the same analogue options as SGR530, plus a choice of digital outputs: RS232, CANbus or USB – up to 10 transducers can be connected to USB.
  Shaft temperature is also measured.
  Self-diagnostics are included, and configuration software allows the sensor to be tuned to the application.
  There is an external ethernet gateway module option.

In both cases, input power is needed at between 12 and 32Vdc.