Sangamo Weston portable voltmeter, England. Precision electrical measuring instruments including A.C. and D.C. voltmeters, designed for accurate voltage measurement in electrical laboratories, power distribution systems, and engineering test environments. Each instrument is housed in a robust portable case with carrying handle and front calibration certificate panel, typical of professional electrical standards equipment used for testing and calibration work. Mid-20th century, c.1940s–1960s.
