Proximity Controls (nowadays - a division of Dwyer Instruments, Inc.) was started in 1965 out of a garage in Fergus Falls, MN. The first product line was the Ultra-Mag Series of diaphragm level controls. The Ultra-Mag offers a unique and patented magnetic drive that seals the switch compartment. Building on their experience with magnetic drives, Proximity expanded into position indicators in 1977 with the invention of the Mark Series.
Like the Ultra-Mag, the Mark Series offers a patented magnetic drive that completely seals the switch compartment. The Proximity Mark Series is a line of position indicators with a selection of various output options. Four model styles make up the Mark series to cover almost any application. Standard models in the Mark Series have visual position indicators and are weatherproof, explosion-proof, and submersible. A large variety of outputs are available to fit specific applications. Besides the switch outputs, the Series offers potentiometer outputs, transmitters, and HART® Communications. The units are purchased for either direct drive applications, such as rotary valves, or lever drive applications, such as linear valves. Adjustable visual indicator is standard on direct drive units that displays OPEN/CLOSED status and degrees.
Proximity Controls was acquired in 1989 by Dwyer Instruments of Michigan City, IN. Proximity Controls is still operated out of Fergus Falls today. Dwyer continues the innovative spirit of Proximity Controls by continually developing new products.