Editing Metal detector (section)

====Gerhard Fischer====

[[Gerhard Fischer (inventor)|Gerhard Fischer]] developed a portable metal detector in 1925. His model was first marketed commercially in 1931; he was responsible for the first large-scale hand-held metal detector development.

Gerhard Fisher studied [[electronics]] at the [[TU Dresden|University of Dresden]] before emigrating to the United States. When working as a research engineer in [[Los Angeles]], he came up with the concept of a portable metal detector while working with [[Aircraft Radio Corporation|aircraft radio]] detection finders. Fisher shared the concept with [[Albert Einstein]], who foresaw the widespread use of hand-held metal detectors.

Fisher, the founder of Fisher Research Laboratory, was contracted by the [[Federal Telegraph Company|Federal Telegraph]] Company and Western Air Express to establish airborne direction finding equipment in the late 1920s. He received some of the first patents in the area of radio-based airborne direction finding. He came across some unusual errors in the course of his work; once he figured out what was wrong, he had the foresight to apply the solution to a totally unrelated area, metal and mineral detection."

Fisher received the patent for the first portable electronic metal detector in 1925. In 1931, he marketed his first Fisher device to the general public, and he established a famous Fisher Labs company that started to manufacture and develop hand-held metal detectors and sell it commercially.<ref>{{Cite web|title=The History of the Metal Detector {{!}} MetalDetector.com|url=https://www.metaldetector.com/learn/metal-detector-history/history-of-the-metal-detector|access-date=10 May 2021|website=www.metaldetector.com}}</ref>