AC SIGNAL MEASURING INSTRUMENT AND ITS OFFSET ADJUSTMENT METHOD

PROBLEM TO BE SOLVED: To provide an AC measuring instrument which can complete offset adjustment quickly by one standard alternating current. SOLUTION: The measuring instrument has a selector switch 11 which is provided halfway between an input circuit 1 and an effective-value conversion circuit 6 to switch a circuit which is routed through a time averaging circuit 10 and a through circuit which is not routed through the time averaging circuit. When the switch 11 is switched to the through circuit, the measuring instrument is ready to receive measurement. With an offset connected to a standard AC generator ready for adjustment, the switch 11 is switched to the time averaging circuit 10, allowing a 0 V offset to be adjusted. With the offset connected to the standard AC generator ready for adjustment, the switch 11 is switched to the through circuit, allowing the difference between a standard alternating current itself from the input circuit 1 and the corresponding scale to be got adjusted. COPYRIGHT: (C)2008,JPO&INPIT