NBR
Butadiene-acrylonitrile copolymer rubber, a material with good oil and chemical resistance

NBR/PVC
A blend of acrylonitrile-butadiene rubber and polyvinyl chloride (PVC). Used for jacketing

NBS
National Bureau of Standards. Now called NIST (National Institute of Standards and Technology)

N Connector
A threaded connecter for coax; N is named after Paul Neill

NEC
National Electrical Code

NEMA
National Electrical Manufacturers Association

Neoprene
A synthetic rubber with good resistance to oil, chemicals and flame. Also called polychloroprene

Network
A series of nodes connected by communications channels

Newton
The derived SI unit for force; the force which will give one kilogram mass an acceleration of one meter per second. Equals 0.2248 pounds force

NFPA
National Fire Protection Association

Nickel Clad Copper Wire
A wire with a layer of nickel on a copper core where the area of the nickel is approximately 30% of the conductor area

NM
A UL cable type. Nonmetallic sheathed cable, braid or plastic covered. For dry use, 90ºC conductor rating

NM-8
A UL cable type

NMC
Nonmetallic sheathed cable, plastic or neoprene covered. Wet or dry use, 90ºC conductor rating

Node
A station

Noise
In a cable or circuit any extraneous sounds or signal which tends to interfere with the sound or signal normally present in or passing through the system

Nomex®
DuPont's trademark for a heat resistant, flame retardant nylon

Nominal
Name or identifying value of a measurable property by which a conductor or component or property of a conductor is identified, and to which tolerances are applied

Nominal Voltage (National Electrical Code)
A nominal value assigned to a circuit or system for the purpose of conveniently designating its voltage class (as 120/240, 480Y/277, 600 etc). The actual voltage at which a circuit operates can vary from the nominal within a range that permits satisfactory operation of equipment

Nomograph
A chart or diagram with which equations can be solved graphically by placing a straight edge on two known values and reading the answer where the straight edge crosses the scale of the unknown value

Nomograph
A chart or diagram with which equations can be solved graphically by placing a straight edge on two known values and reading the answer where the straight edge crosses the scale of the unknown value

Noncontaminating
A type of PVC jacket material whose plasticizer will not migrate into the dielectric of a coaxial cable and thus avoid contaminating and destroying the dielectric

Noncontaminating PVC
A polyvinyl chloride formulation, which does not produce electrical contamination through plasticizer migration

Nonflammable
The property of a material that is not capable of being easily ignited

Nonmigrating PVC
Polyvinyl chloride compound formulated to inhibit plasticizer migration

NRZI
Non-Return to Zero Inverted. A binary encoding technique in which a change in state represents a binary 0 and no change in state represents a binary 1

N-Series Connector
A coaxial connector (RG-8/U) used in standard Ethernet networks

NTSC
National Television Standard Committee. The US color TV standard

Numerical Aperture
The acceptance angle of an optical fiber which determines the angle at which light can enter the fiber; expressed as a number which is equivalent to the sine of the angle

Nylon
An abrasion-resistant thermoplastic with good chemical resistance. Polyamide

North American Hazardous (Classified) Locations