All-Electronic Counter/Timer for Current Meters
H. D. Fisher, J.A. Bondurant · Transactions of the ASAE · 1974
CUP and propeller type current meters originally required an operator to count contact closure noise using earphones. Commercial counters then became available using an electromechanical readout. These counters have problems because either the points in the current meter head carry the current to drive the counter which results in contact burning, or there is an intermediate relay between the points and the counter which introduces another source of possible mechanical failure. The timebase on these units is usually a stopwatch which must be controlled by the operator and has no direct electrical control upon the operation of the counter. The watches are delicate mechanical devices subject to wear and breakage.