Control Dial

A dial designed to be connected to a tuning or selecting mechanism to position the mechanism to some value within its adjustable range. It is designed to be read in conjunction with a vernier indicator, pointer, or like instruments which may or may not be an integral part of the item. May include a knob. For items with one graduation, letter, or symbol, or marked to indicate the position of items such as a valve, brake, or two position switch, see knob or handwheel. See also dial, scale.