NBC suit
An NBC (nuclear, biological, chemical) suit, also called a chemsuit or chem suit or chemical suit is a type of military personal protective equipment. NBC suits are designed to provide protection against direct contact with and contamination by radioactive, biological or chemical substances, and provides protection from contamination with radioactive materials and some types of radiation, depending on the design. It is generally designed to be worn for extended periods to allow the wearer to fight (or generally function) while under threat of or under actual nuclear, biological, or chemical attack. The civilian equivalent is the Hazmat suit. The term NBC has been replaced by CBRN (chemical, biological, radiological, nuclear), with the addition of a new threat, radiological, meaning radiological weapon.
NBC
A variant sequence with an additional note, G-E'-C'-G, known as "the fourth chime", was used during significant events of extreme urgency (including during World War II, especially in the wake of the December 1941 attack on Pearl Harbor; on D-Day and during disasters). The NBC chimes were mechanized in 1932 by Rangertone founder Richard H. Ranger; their purpose was to send a low-level signal of constant amplitude that would be heard by the various switching stations manned by NBC and AT&T engineers, and to be used as a system cue for switching individual stations between the Red and Blue network feeds. Contrary to popular legend, the G-E'-C' notes were not originally intended to reference to the General Electric Company (an early shareholder in NBC's founding parent RCA and whose Schenectady, New York radio station, WGY, was an early affiliate of NBC Red). The three-note sequence remains in use by the NBC television network, most notably incorporated into the John Williams-composed theme music used by NBC News, "The Mission" (first composed in 1985 for "NBC Nightly News").