ELECTRICAL APPARATUS-NAMELY, DIRECT AND ALTERNATING CURRENT AMMETERS, VOLTMETERS, WATTMETERS, VARMETERS, VOLTAMMETERS; BATTERY TESTING VOLTMETERS, LINE CURRENT TESTERS, POWER FACTOR METERS, FREQUENCY METERS, HIGH-FREQUENCY AMMETERS, PORTABLE POTENTIAL TRANSFORMERS AND CURRENT TRANSFORMERS, CYCLE COUNTERS; SWITCHBOARD AND PANEL INSTRUMENTS INCLUDING DIRECT AND ALTERNATING CURRENT AMMETERS, VOLTMETERS, WATTMETERS, VARMETERS, AND FREQUENCY METERS; VACUO JUNCTIONS, AMPERE HOUR METERS, STATIC VOLT...