METHOD AND DEVICE FOR METERING WATTHOUR FOR EVERY TIME ZONE

PROBLEM TO BE SOLVED: To make omittable a power failure backup function by tentatively metering a watthour until current time information can be obtained after the recovery from power failure in case of a power failure and calculating the watthour for every time zone when the current time is obtained. SOLUTION: The metering device 10 of watthour for every time zone where automatic meter reading or the like is applied is provided with a nonvolatile memory 13 where watthour data is written when detecting a power failure, a tentative metering memory 14 that functions when recovering from the power failure. And, when a power failure detection circuit 11 detects the recovery of a commercial power supply after the power failure, the locking of a clock part 12 is started and the watthour of the nonvolatile memory 13 is displayed at a display part 3. The metering value of watthour after recovery from a power failure is successively stored in the tentative metering memory 14, and at the same time, the display part is also updated. The tentative metering memory 14 continues to tentatively meter lapse time and watthour until there is a time reply, for example, by responding to a current time report request from a communication control part 15 and distributes the tentative metering value to a normal time zone and adds it to the value of the nonvolatile memory 13 where time is replied.