possible date made: Circa 1930s
where made: Newark, NJ
model name: Industrial Analyzer
model number: 639
serial number: 3685
Material
Wood
Color
Black
General Notes
Note
Includes instruction manual, designed for alternating currents only, measure 45 to 425 Hz, 3 phase-3 wire & 3 phase-4 wire systems, ammeter is a Transducer type, converts from A.C. amps to .8 milliamps D.C.