Velocity and/or length measuring system - has twin-channel photodetector with standardisation input and averaging stage

摘要

The velocity and/or length measuring system consists of a photo-electric detector which scans the workpiece as it passes. The signals from the detector are converted to digital form and fed to a pulse counter. A standard number of pulses corresponding to the length of the workpiece required can be dialled in by the operator. The outputs of this unit, the pulse counter and a highly accurate clock pulse generator are fed to a data processor. An identical detector at a fixed distance from the first is connected to similar clock generators and counters. The outputs of both counters are averaged. The input allowance pulse - 'pulse standard' - is averaged with the value for the workpiece determined by the detector.