Weston Electrical Instrument 433 AC Voltmeter 0-150V 25-2400 Cycles Portable

Weston Electrical Instrument 433 AC Voltmeter 0-150V 25-2400 Cycles Portable

The Weston Electrical Instrument Corp. Model 433 is a portable analog AC voltmeter measuring AC voltage from 0 to 150 volts across a wide frequency range of 25 to 2400 cycles (Hz). Built by Weston Electrical Instrument Corporation of Newark, New Jersey, this is a classic American-made analog panel meter in a rugged portable bakelite housing with an integrated carry handle. The large, easy-to-read analog dial face is marked "VOLTS A.C. 25-2400 CYCLES" with a clear arc scale from 0 to 150V and resistance-for notations along the bottom edge.

Specifications & What's Included

• Manufacturer: Weston Electrical Instrument Corp., Newark, NJ, USA
• Model: 433
• Serial Number: 36227 (internal reference)
• Measurement type: AC Voltage
• Voltage range: 0–150V AC
• Frequency range: 25–2400 cycles (Hz)
• Display: Analog deflection meter with arc scale
• Front panel: Zero corrector adjustment screw
• Terminals: Binding post input terminals on front panel
• Enclosure: Black bakelite portable case with leather carry handle
• Form factor: Portable bench instrument
• Country of manufacture: USA
• Includes: Meter unit only — no test leads or accessories

Applications

The Weston Model 433 is a mid-20th-century portable AC voltmeter from an era when Weston Electrical Instrument Corporation was one of the most respected names in precision electrical measurement in the United States. Weston meters of this type were standard equipment in industrial plants, electrical utilities, laboratories, and field service settings from the 1930s through the 1960s, used to verify AC line voltage, check transformer outputs, and monitor panel voltages across a broad frequency range — making them especially useful in applications beyond the standard 60 Hz power line, such as aircraft electrical systems, shipboard power, and motor drive circuits operating at non-standard frequencies. The 25–2400 cycle range accommodated everything from low-frequency industrial power to early aircraft AC bus systems. Today, Weston analog meters like this one are sought by collectors of vintage test equipment, restorers of vintage electrical gear, educators demonstrating classical metering principles, and engineers who prefer the real-time analog needle response of a moving-coil instrument for certain monitoring tasks. The rugged portable bakelite case with carry handle made it practical for field use, distinguishing it from fixed panel-mount meters of the same era.