Triaxial Cable, often referred to as triax for short, is a type of electrical cable similar to coaxial cable

Coaxial cable

Coaxial cable, or coax, has an inner conductor surrounded by a flexible, tubular insulating layer, surrounded by a tubular conducting shield. The term coaxial comes from the inner conductor and the outer shield sharing the same geometric axis...

, but with the addition of an extra layer of insulation and a second conducting sheath. It provides greater bandwidth and rejection of interference than coax, but is more expensive. It is most commonly used in the television industry as a connecting cable between a camera

Professional video camera

A professional video camera is a high-end device for creating electronic moving images...

 and its CCU

Camera control unit

- Description :The Camera Control Unit is typically part of a live television broadcast "chain". It is responsible for powering the professional video camera, handling signals sent over the camera cable to and from the camera, and can be used control various camera parameters such as iris...

. The outer sheath is commonly used as a protective earth conductor. The core provides both power and signal connections, with the return for the power being provided through the inner screen. Through frequency-division

Frequency-division multiplexing

Frequency-division multiplexing is a form of signal multiplexing which involves assigning non-overlapping frequency ranges to different signals or to each "user" of a medium.- Telephone :...

 multiplexing

Multiplexing

The multiplexed signal is transmitted over a communication channel, which may be a physical transmission medium. The multiplexing divides the capacity of the low-level communication channel into several higher-level logical channels, one for each message signal or data stream to be transferred...

, the camera can send audio and video signals along the triax while the CCU can send camera control information, such as exposure settings, intercom, return audio and video (usually that of the program), and tally (a signal alerting the operator that their camera is on the air)and power for the camera.

Venues that host television productions fairly often, such as sports arenas, will usually have triaxial cables run from the location of the TV truck to common camera locations throughout the building. This allows a shorter and easier workday for visiting television crews, who can simply plug into existing cable runs instead of having to run their own and tear them down after the shoot.

• In 1992 N.V. Philips
  Philips
  Koninklijke Philips Electronics N.V. , more commonly known as Philips, is a multinational Dutch electronics company....
  
  , Breda
  Breda
  Breda is a municipality and a city in the southern part of the Netherlands. The name Breda derived from brede Aa and refers to the confluence of the rivers Mark and Aa. As a fortified city, the city was of strategic military and political significance...
  
   received the Outstanding Achievement in Technical/Engineering Development Award from the National Academy of Television Arts & Sciences for Triaxial cable Technology for Color Television Cameras. Also see Norelco
  Norelco
  Norelco is the American brand name for electric shavers and other personal care products made by the Consumer Lifestyle division of Philips.-Norelco and Philishave:...
  
   and BTS
  Broadcast Television Systems Inc.
  Broadcast Television Systems was a joint venture between Robert Bosch GmbH's Fernseh Division and Philips Broadcast in Breda, Netherlands formed in 1986.- History :...
  
  

Another application for triaxial cables is in taking precision low-current measurements. The core (known as the force) and the inner shield (known as the guard) are kept at the same electrical potential, thus the leakage current between them is zero for all practical purposes, despite the imperfections of the insulation. Instead, the leakage current occurs between the inner and outer shields, which does not matter, because it is the core that is connected to the device under test

Device under test

Device under test , also known as unit under test , is a term commonly used to refer to a manufactured product undergoing testing.-In semiconductor testing:...

and the core current is the one being measured.