Redundant pulses generated by independently operable pulse sources in an electricity meter are accumulated as pulse counts in a pair of channels of a multi-channel recorder. The pulse counts are compared to verify the accuracy of the pulses counted by each channel. If the difference between the values...http://www.google.com/patents/US4999572?utm_source=gb-gplus-sharePatent US4999572 - Redundant pulse monitoring in electric energy metering system
