Plotting torque against shaft position

By combining and comparing the readouts from these two instruments, it becomes possible to plot instantaneous torque values against the angle of a shaft.

Typically, the need is to measure peaks and troughs in torque against the instantaneous angle of the shaft, or to build a complete model of a driven system's performance against a baseline of time or shaft rotation. Such information could then be used to optimise the operation of pumps and fans, tools such as screws and drills, systems such as cap tighteners and motion mechanisms, and even the driving characteristics of electric vehicles.

The SGR523 encoder is of incremental format, rather than absolute. If absolute shaft position is required, an optional index home pulse can be connected to the angle zero input of the transducer. This will reset the angle encoder back to zero once per rotation.

In use the encoder's in-phase and quadrature-phase signals are read by the torque sensor and combined with its own output signals to produce a pulse-RPM signal which will have a resolution of twice the encoder pulses. Optionally the in-phase and quadrature-phase encoder signals can also be read and recorded, to enable tracking of rotational direction information.

The maximum operational speed of the combined TorqSense/encoder unit depends on the encoder resolution: a 2048 pulses per revolution encoder can operate at a maximum speed of 9000 RPM, while a 10,000 pulses per revolution encoder can operate at a maximum speed of 1500 RPM.