Glossary of Terms


(ID)Inner Diameter

The diameter of the inside of a tube, pipe or other object. Often abbreviated "ID"

(OD)Outer Diameter

The outer diameter of a pipe, including the wall thickness; usually measured with calipers. Abbreviated OD.


An abrasion is a wound caused by superficial damage to the skin, no deeper than the epidermis. It is less severe than a laceration


Fibers are a class of heat-resistant and strong synthetic fibers. They are used in aerospace and military applications, for ballistic rated body armor fabric and ballistic composites, in bicycle tires, and as an asbestos substitute.


In physics, attenuation (in some contexts also called extinction) is the gradual loss in intensity of any kind of flux through a medium. For instance, sunlight is attenuated by dark glasses, X-rays are attenuated by lead, and light and sound are attenuated by water.


A dividing wall or barrier between compartments in a ship, aircraft, or other vehicle.


In physics and electrical engineering, a conductor is an object or type of material that allows the flow of electrical current in one or more directions. For example, a wire is an electrical conductor that can carry electricity along its length.


The definition of continuity refers to something occurring in an uninterrupted state, or on a steady and ongoing basis.


The flow of electrons through a metallic circuit, like the flow of water down a riverbed .The direction of flow is from positive (+) pole to negative (-).

Dielectric strength

In physics, the term dielectric strength has the following meanings: Of an insulating material, the maximum electric field that a pure material can withstand under ideal conditions without breaking down (i.e., without experiencing failure of its insulating properties).

Drain Wire

A wire wrapped around or part of a shield within a cable that reduces the resistance from any point on the shield to ground. A drain wire serves to complete an electrical circuit from the shield, thereby carrying extraneous electrical noise to ground and away from the circuit or system the shield is intended to protect.


A device that operates on the basis of electromagnetic fields and that contains few, if any, mechanical components. A solenoid is an example of an electromagnetic device.

Electromagnetic shielding

is the practice of reducing the electromagnetic field in a space by blocking the field with barriers made of conductive or magnetic materials. Shielding is typically applied to enclosures to isolate electrical devices from the 'outside world', and to cables to isolate wires from the environment through which the cable runs. Electromagnetic shielding that blocks radio frequency electromagnetic radiation is also known as RF shielding.


(Electromagnetic Interference) Interference with a desired signal caused by the coupling of an undesired signal due to electromagnetic radiation. The source of the electromagnetic interference may be natural, such as solar radiation, or artificial, such as a generator, compressor, fluorescent light, or electrified copper circuit. The radiation may be in many forms, including radio waves, light waves, and gamma rays. Unshielded twisted pair (UTP) and radio circuits are particularly susceptible to EMI. EMI that is in the radio frequency range is known as radio frequency interference (RFI).

Erosion corrosion

Also known as impingement damage, is the combined effect of corrosion and erosion caused by rapid flowing turbulent water. It is probably the second most common cause of copper tube failures behind Type 1 pitting which is also known as Cold Water Pitting of Copper Tube.


An external metal or plastic structure added to increase streamlining and reduce drag, especially on a high-performance car, motorcycle, boat, or aircraft.

Flame Retard

Flame retardants are compounds added to manufactured materials, such as plastics and textiles, and surface finishes and coatings that inhibit, suppress, or delay the production of flames to prevent the spread of fire. They may be mixed with the base material (additive flame retardants) or chemically bonded to it (reactive flame retardants). Mineral flame retardants are typically additive while organohalogen and organophosphorus compounds can be either reactive or additive.

Fluid Dynamics

In physics, fluid dynamics is a subdiscipline of fluid mechanics that deals with fluid flow—the natural science of fluids (liquids and gases) in motion. Hydrodynamic = relating to, or operated by the force of liquid in motion.

Fluid Resistance

The force exerted by a gas or liquid opposing the motion of a body through it. Also known as resistance.


Fungicides are biocidal chemical compounds or biological organisms used to kill or inhibit fungi or fungal spores.

Ground Wire

A conductor that leads from a circuit, shield, or system to an electrical connection to the ground, generally through a ground rod driven into the earth.


To protect from blast, heat, or radiation (as by a thick barrier or placement underground).

Material Strength

Strength of materials, also called mechanics of materials, is a subject which deals with the behavior of solid objects subject to stresses and strains. The complete theory began with the consideration of the behavior of one and two dimensional members of structures, whose states of stress can be approximated as two dimensional, and was then generalized to three dimensions to develop a more complete theory of the elastic and plastic behavior of materials.

Mil Spec

A United States defense standard, often called a military standard, "MIL-STD", "MIL-SPEC", or (informally) "MilSpecs", is used to help achieve standardization objectives by the U.S. Department of Defense.


A mooring refers to any permanent structure to which a vessel may be secured. Examples include quays, wharfs, jetties, piers, anchor buoys, and mooring buoys. A ship is secured to a mooring to forestall free movement of the ship on the water.


Unwanted disturbances superimposed on a signal and interfering with its integrity. Noise can be introduced by equipment or can be the result of natural phenomena. Noise can take a number of forms, including amplitude noise, cross-talk, echo, intermodulation noise, harmonic distortion, impulse noise, random noise, and white noise.


Polyester, is a category of polymers that contain the ester functional group in their main chain. As a specific material, it most commonly refers to a type called polyethylene terephthalate (PET).


Polyurethane is a polymer composed of a chain of organic units joined by carbamate links. While most polyurethanes are thermosetting polymers that do not melt when heated, thermoplastic polyurethanes are also available.


A prototype is an early sample, model, or release of a product built to test a concept or process or to act as a thing to be replicated or learned from. It is a term used in a variety of contexts, including semantics, design, electronics, and software programming.


Electromagnetic interference (EMI) that is within the radio frequency range of the electromagnetic spectrum. See also electromagnetic spectrum and EMI.


The Restriction of Hazardous Substances Directive 2002/95/EC, (RoHS ), short for Directive on the restriction of the use of certain hazardous substances in electrical and electronic equipment, was adopted in February 2003 by the European Union.

SAE J2302

This procedure measures the resistance to radiant heat flow of insulating materials in sleeve form. The sleeve's effectiveness (SdE) is determined by measuring the difference in surface temperature of a flat black, single- diameter ceramic cylinder with and without the standard diameter sleeve at the specified temperature, position, and distance from the radiant heat source.


Is the length of time that a commodity may be stored without becoming unfit for use or consumption. It applies to foods, beverages, pharmaceutical drugs, chemicals, and many other perishable items.


A covering, sheath, or screen designed to protect a signal traveling over a conductor from electromagnetic interference (EMI) due to the unwanted coupling of extraneous signals .The shield is in the form of a conductive metal foil, screen, or braid that surrounds a conductor or group of conductors. A dielectric material insulates the conductors from each other and from the shield, which essentially is an outer conductor that intercepts extraneous signals and conducts them to ground. Therefore, the shield must be continuous and must be grounded via a ground wire, or drain wire. To ensure electrical continuity, the shield must be bonded at any splice points and the shield must be bonded to the ground wire, strap, or rod.

Signal-to-noise ratio

The ratio of the power or volume (amplitude) of a signal to the amount of disturbance (the noise) mixed in with it. Measured in decibels, signal-to-noise ratio (SNR, S/N) measures the clarity of the signal in a circuit or a wired or wireless transmission channel.

Tear strength

In simpler terms tear resistance (or tear strength) is a measure of how well a material can withstand the effects of tearing. More specifically however it is how well a material (normally rubber) resists the growth of any cuts when under tension, it is usually measured in kN/m. Tear resistance can be measured by the ASTM D 412 method (the same used to measure tensile strength, modulus and elongation).

Temperature range

Atmospheric temperature range is the numerical difference between the minimum and maximum values of temperature observed in a given location during a period of time (e.g., in a given day, month, year, century) or the average (average of all temperature ranges in a period of time).


the quality or fact of being able to grip something firmly; grip.

Tensile Strength

The maximum stress it withstands before failing is its ultimate tensile strength. Ultimate tensile strength (UTS), often shortened to tensile strength (TS) or ultimate strength, is the maximum stress that a material can withstand while being stretched or pulled before failing or breaking.

Thermal insulation

Materials used to reduce the rate of heat transfer Longitudinal Shrinkage Insulator (electrical), the use of material to resist the electric current and magnetism.


In fluid dynamics, turbulence or turbulent flow is a flow regime characterized by chaotic property changes. This includes low momentum diffusion, high momentum convection, and rapid variation of pressure and flow velocity in space and time.

U.V. Resistance

UV resistance in textiles refers to a fiber's or fabric's ability to resist UV radiation.


UL was established in 1894 and has participated in the safety analysis of many of the last century's new technologies, most notably the public adoption of electricity and the drafting of safety standards for electrical devices and components.


Electric potential, expressed in volts (V).Voltage is the push, or pressure, behind current flow.