AMPROBE

ELECTRICAL RECORDING AND [ INDICATING INSTRUMENTS-NAMELY, VOLTMETERS, AMMETERS, VOLT-AMMETERS, STEP-UP AND STEP-DOWN DEVICES USABLE WITH VOLT-AMMETERS, CIRCUIT TRACERS, VOLT AND AMPERAGE RECORDING INSTRUMENTS, NULL-BALANCE ] MEASURING INSTRUMENTS [ , DEVICES FOR AMPLIFYING MEASURING INSTRUMENTS, OUTPUT AND AUTOMATIC INSTRUMENT CONTROLLING SWITCHES ]