DeJur-Amsco Corporation of Connecticut, was founded in the 1920s by Ralph and Harry DeJur. They started with a focus of building components and testers for the radio tuning, the hot new technology of the time. They received a number of patents for capacitors and condensers and the company grew.
A decade later they branched out to make photography equipment starting with light meters. They were a supplier of equipment to the military during WWII. After the war they became known as the best quality and most accurate meters, advertising them as “military war proven”.