Standard wavemeters

To serve as a standard of radio frequency the Bureau of Standards has two specially constructed wavemeters covering the frequencies in moregeneral use from 18 to 4600 kilocycles per second (16,650 to 65 meters). These standard wavemeters are used in calibrating wavemeters belonging to the Radio Inspection Service, manufacturers, colleges or others in need of standards of frequency, in radio measurements and in adjusting the radio transmitting set which is used to transmit standard frequency signals.