Check the listing for details. Vintage A.C. Voltmeter Model 33O Weston Iron Core Electrodynamoter Bakelite. Condition: Used. Listed at 60.00 USD. The vintage A.C. Voltmeter Model 33O by Weston is a classic piece of equipment used for measuring AC currents. The Weston brand is known for its precision and reliability in the field of electrical testing and measurement. This iron core electrodynamic meter features a bakelite construction, making it durable and resistant to wear and tear. Perfect for businesses and professionals in the industrial sector, this voltmeter offers accurate readings for a variety of electrical applications. Not tested selling as is.