An incremental encoder that uses precision measuring
wheels to directly measure the movement of a conveyor belt, or to accurately
measure moving material.
Wheeled encoders more accurately track
the conveyor belt or other material than shaft encoders. Two problems with shaft
encoders in this application are: (1) slippage of the conveyor belt on the
roller, and (2) inaccuracy of roller diameters. Both of these contribute to
inaccuracies that reduce the overall efficiency of a material handling sortation
system or precision measuring system.
Wheeled encoders ride directly on the moving material, use a wheel tread having a
high coefficient of friction, and have a very low starting torque resulting in
virtually no slippage of the wheels on the belt. In addition, the wheels are
precision ground with exacting
tolerances, versus a roller which has a much larger
tolerance and its circumference seldom translates into an integral number of
encoder pulses per unit of linear movement.
Photocraft models RH, R21, and R22 wheeled encoders offer additional advantages.
