Abstract: This disclosure deals with a system for monitoring the rate of operation of a cyclically operating machine or process or the rate of cyclically recurring events. The system monitors the rate by sensing each cycle occurring during a sampling time interval or duration and generating a signal which is taken as a standard value representing a standard rate. Either the length of time required for a specific number of events is measured, or the number of events occurring in a specified time is measured. The measured value is compared with the standard value and an indication is made of the comparison.