ABSTRACT
From relying on the accuracy of our eyesight to using straightedges and feeler gauges and
then eventually to shaft clamping brackets and dial indicators, the science of measuring
machinery shaft positions has been continually investigated to include new and innovative
measuring devices, particularly in light of the technological explosion in electronics. With the
advent of the microprocessor chip, silicon photodiodes, and the semiconductor junction diode
laser, new inroads have been forged in the process of measuring rotational centerlines that
utilize these new electronic devices.
