Part Numbers & Connector (3)
Technical References (4)
Certifications & Standards (5)
Searching on website (5)
Environementally Sealed (2)
Fiber Optic Connector (4)
Robotic Applications (3)
Before LEMO can assist with a mating plug part number, we must first identify the LEMO receptacle.
First, check your equipment documentation to see if the LEMO part number is included.
If not, check the equipment manufacturer's web site to determine if they reference this information.
If the first two steps do not yield a LEMO part number download a Receptacle Identification Guide for more assistance.
Yes. LEMO's distinctive "chocolate plate" connector design is a registered trademark US Reg 2'703'464 and Europe Registration 798'106
The mark consists "...of truncated pyramidal projections formed on an outer surface of a connector, and with each truncated pyramidal projection having a square based on a square top"
The 5th letter of a LEMO part number is an indication of the connector series. Other information needed to determine a full part number is as follows: How many contacts (pins) are in the insert of the connector? Is the shell soft chrome plated brass shell? Are the terminations solder or crimp? What is the diameter of the cable entering the rear of the connector (in millimetres if possible)? Is there a bend relief (strain relief) at the transition between the connector and the cable? What is the colour of the connector?
See Part Numbers Explained for more information about LEMO's part numbering system.
LEMO determines its published Operating Voltage V(signal) specifications as follows:
V(test) = 0.75 x V(breakdown)
V(signal) < 1/3 x V(test)
V(breakdown) = Mean breakdown voltage
V(test) = Test Voltage
Substituting V(test) in equation (2) through V(test)
from equation (1) yields equation (3):
V(signal) = 1/3 x 0.75 x V(breakdown) = 1/4V(breakdown)
•High Voltage contact
A LEMO plug is typically marked with the LEMO name and the first 5 characters of the part number, which represent the model, size, and series.For more information, download a detailed Plug Identification Guide A LEMO receptacle is typically marked with the LEMO name and the first 5 characters of the part number, which represent the model, size, and series.For more information, download a detailed Receptacle Identification Guide
Here are the NEMA 250 classifications:
|1||Intended for use primarily to provide a degree of protection against limited amounts of falling dirt.|
|3||Outdoor protection against rain, sleet, windblown dust, and damage from external ice formation.|
|3R||Outdoor, protection against rain, sleet, and damage from external ice formation.|
|3S||Outdoor, protection against rain, sleet, windblown dust, and to provide for operation of external mechanisms when ice laden.|
|4||Indoor/Outdoor, protection against windblown dust and rain, splashing water, hose-directed water & damage from external ice formation.|
|4X||Indoor/Outdoor, protection against corrosion, windblown dust and rain, splashing water, hose-directed water & damage from external ice formation.|
|6||Indoor/Outdoor, protection against hose-directed water, the entry of water during occasional temporary submersion at a limited depth & damage from external ice formation.|
|6P||Indoor/Outdoor, protection against hose-directed water, the entry of water during prolonged submersion at a limited depth & damage from external ice formation.|
|12||Indoor, protection against circulating dust, falling dirt and dripping non-corrosive liquids.|
|12K||Type 12 with knockouts|
|NEMA Enclosure||IEC Enclosure|
|4 & 4X||IP56|
|6 & 6P||IP67|
|12 & 12K||IP52|
International Electrotechnical Commission - IEC 60529 "Degrees of protection provided by enclosures (IP Code).". NEMA offers a similar rating system.
Definition of degree of protection (IP code)
IEC 60529 outlines an international classification system for the sealing effectiveness of enclosures of electrical equipment against the intrusion of foreign bodies (e.g., tools, dust, fingers, and moisture) into the equipment. This classification system utilizes the letters IP (Ingress Protection) followed by two digits.
Degree of protection - First digit
The first digit of the IP code indicates the degree that the connector is protected against contact with moving parts, as well as the degree to which equipment is protected against solid foreign bodies intruding into an enclosure:
0 No special protection.
1 Protection from a large part of the body such as hand or from solid objects greater than 50 mm in diameter.
2 Protection against objects not greater than 80 mm in length and 12 mm in diameter.
3 Protection from entry by tools, wires, etc., with a diameter or thickness greater than 2.5 mm.
4 Protection from entry by solid objects with a diameter or thickness greater than 1.0 mm.
5 Protection from the amount of dust that would interfere with the operation of the equipment.
Degree of protection - Second digit
The second digit indicates the degree of protection of the equipment inside the enclosure against the harmful entry of various forms of moisture (e.g., dripping, spraying, submersion, etc.).
0 No special protection.
1 Protection from vertically dripping water.
2 Protection from dripping water when tilted up to 15°.
3 Protection from sprayed water.
4 Protection from splashed water.
5 Protection from water projected from a nozzle.
6 Protection against heavy seas, or powerful jets of water.
7 Protection against temporary immersion.
8 Protection against complete continuous submersion in water (up to 1 meter deep for 15 minutes).
All LEMO connectors with solder-style contacts are fully compatible with lead-free solder and the required higher temperatures. LEMO insulators are made of high temperature material and the standard connecting surfaces are made of an Au/Ni plating. In addition, LEMO has conducted verification testing of contacts and cable assemblies with lead-free solder.
Standard cable and product assemblies from LEMO use lead-free solder. Cable assemblies and other value added products that require RoHS declarations of compliance will be available by June 1, 2006. Call us if you need help with certification earlier. LEMO also continues to offer custom services to meet customer specific requirements for both material and process (such as with solder selection) in cable and other product assemblies. Lead based or lead-free soldering processes are available.
LEMO's F & M Series connectors meet or exceed performance requirements of military standards (MIL spec such as MIL 810F but are currently not compatible with D38999 in dimensions connectors.
|Test Voltage rms||1344A||3001.1|
|Rated Voltage rms||1344A||3001.1|
|Shell Electrical Continuity||1344A||3007|
|VSWR f (Ghz)||1344A||3005|
|Straight Pull force on Cable||1344A||2009.1|
|Insertion Force on Contacts||1344A||2014|
|Retention Force on Contacts||1344A||2007.1|
|Vacuum Test (if applicable)||1344A||1008|
|Hydrostatic Pressure Resistance (if applicable)||1344A||1006.1|
|Humidity Dependence of Working Voltage||1344A||1002.1|
|Fluid contamination (Fuels, gasoline…)||810F||504|
|Sand and dust (6 hr, 55°C, blowing < 150 μm dust)||810F||510.4|
|Gunfire vibration (25 to 2000 Hz, 3 axis (Apache helicopter))||810F||519.5|
|Vibration-Sine (30 g, 3 axis, 12 hr)||202||204-G|
|Acceleration (50g)||1344||2011-1, A|
NIM modules (Nuclear Instrumentation Methods) are used to collect scientific data in nuclear particle research.
The 3K.93C Series is used in the High Definition Television (HDTV) industry.
A low voltage contact has no additional protection, such as an insulating sleeve, and is intended to run low voltages.
A high voltage contact has an additional insulating sleeve that provides longer creepage distances.
A coaxial contact is a concentric mechanical design to achieve a given electrical impedance.
A triaxial contact is a coaxial contact with an additional shielding.
A quadrax connector design has a center contact plus three concentric contacts, allowing connection of four wires.
A thermocouple is an electric temperature sensor consisting of two different metals.
Fluidic contacts for medical, dental and industrial applications allow you to connect single or multiple tubes and hybrid electrical/fluidic cables. They can also be used for air.
LEMO offers a variety of ceramic and metal ferrules that can accept different fibers.
Shell Style is a way of grouping connectors into categories. The most common shell styles are free (straight or elbow) plugs and fixed (front/rear mount) receptacles.
Insert Style groups various contact configurations, such as single contact, multiple contact, coaxial, fiber optic, hybrid, etc.
Termination Style describes how you connect your cable or printed circuit board to the connector.
Crimp: used for stranded wires.
Printed Circuit Board: has straight leads.
Elbow-PCB: has 90 degree elbow leads to a through-hole printed circuit board.
Fiber optic terminates, optical fiber, and Fluidic/Pneumatic: intended for tubes.
Thermocouple: special solder contacts for sensors based on the thermoelectric effect.
Low Voltage contact(s)
High Voltage contact(s)
Fiber optic contact(s)
Coaxial or triaxial impedance (50 or 75 Ohm)
Diameter in mm (unless specified otherwise)
Printed Circuit Board
Elbow (90 degree) design for printed circuit board
Common typographical errors include:
Using the digit "5" instead of the letter "S" and vice-versa
Using the letter "I" instead of the digit "1"
Using the letter "7" instead of the letter "Z" and vice-versa
If you cannot resolve this issue, please contact us at firstname.lastname@example.org for further assistance.
Check your color requirement. Your connector of choice might be in the database in other colors (contact LEMO to get your color).
Clear the Cable Ø fields and repeat the search.
Do not specify a connector diameter or length unless it is absolutely critical.
Try the S Series instead of B and vice versa (same for E and K).
Choose a different Shell Style.
Try both solder and crimp termination, or printed circuit board (PCB).
You can also use the Connector Design Connector Quote Form for further assistance from LEMO (typically takes one business day).
Change the sequence if you want to modify more than one parameter, or go to the advanced search page and start over.
For example, the 2B.708 insert has one high voltage contact (8,000 Volts, 4 Amps) and eight low voltage contacts (750-1,500 Volts, 10 Amps).
- Seal between the plug and receptacle
- Seal between the receptacle and the panel
- Seal between the plug and the cable
IP68 is achieved for points 1 and 2. The connector to cable seal is highly dependant on the shape of the cable, therefore it can range from IP66 to IP68.
Example: the FGG.3K.03A.CLZC65 is a straight plug with a cable collet and two holes for fiberoptic contacts . Note that you must order the two fiber optic contacts separately.
For advice on terminating the various types of LEMO fibre optic connectors please contact your local LEMO supplier.
Instructions include the following guide lines
- 900um Buffered Fibre
- Tight Jacket Cable
- Multiway Optical Cable
- Multiway Hybrid Cable
- Hand Polishing Instructions
- Machine Polishing Instructions
Due to the wide variation in content and format request forms, LEMO adopted its own forms in response to requests for regulatory information. If part number is specified by the Customer, LEMO can supply a COC with mention of the LEMO part number, RoHS compliance status and number of exemption (if applicable). Please submit your request using your usual communication channel (subsidiary, distributor).
European regulation N° 1907/2006, adopted in December 2006, that establishes a single integrated system for the registration, evaluation, authorisation and restriction of chemical substances in the European Union. It applies to all areas of activity.
Due to the wide variation in content and format request forms, LEMO adopted its own forms in response to requests for regulatory information. LEMO can provide upon request Material Declarations on LEMO template for some specific products. Please submit your request using your usual communication channel (subsidiary, distributor).
The substances restricted under RoHS are lead (Pb), mercury (Hg), cadmium (Cd), hexavalent chromium (Cr6+), polybrominated biphenyls (PBB), polybrominated diphenyl ethers (PBDE), and four different phthalates (DEHP, BBP, BBP, DIBP).
A homogeneous material is either a material with a uniform composition throughout or a material that consists of a combination of materials, that cannot be disjointed or separated into different materials by mechanical actions such as unscrewing, cutting, crushing, grinding or abrasive processes.
Article 33 requires that any supplier of an article in the EU containing SVHCs above the threshold of 0.1% weight by weight must provide sufficient information to the customer to allow safe use of the article.
Sony designates suppliers that cooperate in the production of environmentally sensitive products as Green Partners. Sony established the "Sony Green Partner Standards" in 2001 with the aim of encouraging suppliers to introduce Green Partner environmental management systems.
LEMO is committed to follow the "Green Partner Environmental Quality Approval Program" where the controlled substances are described. This document (SS-00259) regroups REACH and RoHS and other National regulations from different countries.
Under this commitment LEMO performs regular controls of all suppliers, ICP tests, Audits, self-evaluation and staff training, among others.
Feed-Thru: A connector or terminal block usually having double-ended terminals which permit simple distribution and bussing of electrical circuits. Also used to describe a bushing in a wall or bulkhead separating compartments at different pressure levels with terminations on both sides.
Ferrule: A short tube used to make solder-less connections to shielded or coaxial cable. In fiber optics, a tube with a central hole that holds the fiber in a connector.
Fiber (fiber Optic): A short tube used to make solder-less connections to shielded or coaxial cable. In fiber optics, a tube with a central hole that holds the fiber in a connector.
Fiber Optics (F.O.): A general term describing a lightwave or optical communications system. In such a system, electrical information is converted to light energy, transmitted to another location through optical fibers and is there converted back into electrical information.
Flange: A mechanical shoulder on the outside housing, enabling attachment to a panel; can also allow for seals with gaskets or o-rings.
Flexible: That quality of a cable or cable component which allows for bending under the influence of outside force, as opposed to limpness, which is bending that occurs due to the cable's own weight.
Fluorinated Ethylene Propylene (FEP): FEP is similar to polytetrafluoroethylene (PTPE) but has a melting point of about 50° C lower and slightly different physical properties.
Frequency: The number of times an alternating current repeats its cycle in one second, expressed in cycles per second, or Hertz (Hz).
Front Mounted: A connector is front mounted when it is attached to the outside or mating side of a panel. A front mounted connector can only be installed or removed from the outside of the equipment.
Gasket: A component made from an elastomer, such as rubber, to provide an environmental seal in the interface of a connector pair. Also called a "grommet".
Giga: A numerical prefix denoting one billion (109)
Graded Index Fiber (Fiber Optic): A multimode fiber whose core refractive index increases in controlled fashion outward from the axis and matches the cladding refractive index at the core-clad interface. Has greater bandwidth than step index fiber, but less bandwidth than single mode fiber.
Ground (GRD): An electrical term meaning to connect to the earth or other large conducting body to serve as an earth, thus making a complete electrical circuit. Sometimes at zero potential or voltage.
Hard Clad Silica (Fiber Optic): Abbreviated HCS, it is a structure in fibers where the cladding around the glass core is a hard plastic, as opposed to a "PCS," which is a soft plastic cladding.
Heat Shrinkable: The term describing tubes, sleeves, caps, boots, films, or other forms of plastic which shrink to encapsulate, protect or insulate connections, splices, terminations, and other configurations.
Hermetic: Permanently sealed by fusion, soldering, or other means to prevent the transmission of air, moisture vapor, and all other gases. Hermeticity is usually expressed as the rate of leakage volume of tracer gas (such as helium) per second in time.
Hertz (Hz): Unit of frequency equal to one cycle per second.
High Definition Television: Abbreviated as HDTV, a recent form of broadcast of television signals in a significantly higher resolution providing images of superior quality. HDTV signals in the studios and arenas are normally carried over optical fibers due to the high bandwidths required for the digitized signal data.
Hi-pot: A test designed to determine the highest potential that can be applied to a conductor without breaking through the insulation.
High Voltage: Generally, a wire or cable with an operating voltage of over 600 volts.
Holding Strength: The ability of a connector to remain assembled to a cable when under tension.
Housing: The main or largest portion of a connector to which other portions are attached or enclosed.
Impedance (Z): The total opposition that a circuit offers to the flow of alternating current or any other varying current at a particular frequency. It is a combination of resistance R and reactance X, expressed in ohms and designated by Z.
Infrared (Fiber Optic): Light with wavelengths 700-1000 nm, invisible to the eye, and felt as heat.
Inner Conductor: The central conductive member in a coaxial structure, such as the center contact in a coaxial connector.
Insert: That part which holds the contacts in their proper arrangements and electrically insulates them from each other and from the shell. Also called dielectric, insulator, or dielectric support.
Insert Retention: The axial load in either direction that an insert must withstand without being dislocated from its normal position in the connector shell.
Insertion Loss: The loss in load power resulting from the insertion of a cable, component, or device. It is expressed in decibels as the ratio of power received at the load before insertion to the power received at the load after insertion.
Insertion Tool: A small, hand-held tool used to insert contacts into a connector.
Insulation: A material which offers high electrical resistance, making it suitable for covering components, terminals, and wires. This prevents the possible future contact of adjacent conductors resulting in a short circuit.
Insulation Resistance: The ratio of the applied voltage to the total current between two electrodes in contact with a specific insulator.
Interface: (1) A shared boundary;(2) The two surfaces on the contact side of both halves of a multiple-contact connector that face each other when the connector is assembled; (3) In fiber optics, the surface where two materials meet, as in core-cladding interface, or fiber-to-fiber interface in a connector.
ISO: Abbreviation for International Organization for Standardization.
Jacket: An outer non-metallic protective covering applied over an insulated wire or cable.
Key: A short pin or other projection which slides in a mating slot or groove to guide two parts being assembled. Generally used in round, shell-enclosed connectors to prevent mating wrong connectors and to assist in polarization.
Keyway: The slot or groove in which a key slides.
Kilo: A numerical prefix denoting 1000 (10³)
Laser (Fiber Optics): An acronym for "light amplification by stimulated emission of radiation," a device that generates intensified light, usually very directional and over a narrow range of wavelengths. Often a source of light in fiber optic systems.
Light (Fiber Optic): An electromagnetic radiation in the wavelength range including infrared, visible, ultraviolet, and X rays, usually the range visible to the human eye, i.e., the energy that enables vision. Light travels in a vacuum at 300,000 km/sec. (186,281 miles per second).
Lightguide (Fiber Optic): A fiber or a flexible bundle of fibers used to transmit light.
Loose Buffer (Fiber Optic): Also called "loose tube," a protective tube loosely surrounding a cabled fiber, often filled with a gel.
Loss: Energy dissipated without accomplishing useful work, attenuation, usually expressed in dB.
Lug: A mechanical termination, usually crimped or soldered to the conductor, with provision for threading on to a terminal; hardware.
Mate: To join two connector halves in a normal engaging mode.
Mega: A numerical prefix denoting one million (106).
Meter: Unit of length, equal to 39.37 inches.
Micro: A numerical prefix denoting one-millionth (10-6).
Micrometer: One millionth (10-6) of a meter, a unit of length. Used to specify wavelengths.
Micron: (Short for the preferred form "micrometer"): a measure of length equal to 10-6. Used to specify wavelength, it is equal to 1000 nanometers, the preferred term.
Mil: (0.001"): A unit used in measuring the diameter of wire or thickness of insulation over a conductor.
Milli: A numerical prefix denoting one thousandth (10-3).
Mode (Fiber Optic): One of the components of a general configuration of a propagating wave front. Mode is characterized by a particular geometrical pattern and propagation constant.
Moisture Resistance: The ability of a material to resist absorption of moisture.
Multimode Fiber (Fiber Optic): A fiber that transmits many modes.
Nano: A numerical prefix denoting one-billionth (10-9).
Near Infrared: The part of the infrared electromagnetic spectrum near visible wavelengths, in the range of 700 to 1500/2000 nm.
O-Ring: An elastomer gasket enabling a moisture seal, having a circular cross section. See Rubber.
Ohm: Unit of electrical resistance. Resistance of a circuit in which a potential difference of one volt produces a current of one ampere.
Outer Conductor: The external conductive member in a coaxial structure, such as the housing in a coaxial connector.
Overall Diameter: Finished diameter over wire or cable.
Oxidation: Oxidation can be considered the simple addition of oxygen to a metal, e.g., the addition of atmospheric oxygen to iron to form familiar rust. See Corrosion.
PTFE: Abbreviation for polytetrafluoroethylene, commonly known as Teflon.
Phosphor Bronze: This strong and relatively hard alloy is used to fabricate metal parts and springs. Phosphor bronze is resistant to corrosion.
Photon: A quantum of electromagnetic radiation, a unit of light. Light can be viewed as a series of photons.
Physical Contact (Fiber Optic): Abbreviated as PC, this is a design feature of fiber optic connectors, where the mating contacts' faces are in contact and under pressure provided by springs, resulting in lower loss.
Pico: A numerical prefix denoting one-millionth of one-millionth (10-12).
Pin Contact: A male-type contact, usually designed to mate with a socket or female contact. It is normally connected to the "dead" side of a circuit.
Pinholes: Small holes visible on the surface of soldered joints, which generally indicate the presence of a larger void within the joint. Typically caused by the generation of gas during solidification due to presence of salts and water. Sometimes called blowholes.
Plastic Clad Silica (Fiber Optic): A fiber structure where the cladding around the core is a soft plastic, abbreviated PCS.
Plastic Fiber: An optical fiber made of plastic alone.
Plating: The overlaying of a thin coating of noble metal on metallic components to improve conductivity, provide for easy soldering or prevent rusting or corrosion.
Plug: The part of the two mating halves of a connector that is free to move when not fastened to the other mating half. The plug is usually thought of as the male portion of the connector. The plug may have female contacts if it is the "free to move" member.
Polarization: The arrangement of mating connectors such that the connectors can be mated in only one orientation.
Polarizing Pin, Key, or Keyway: A device incorporated in a connector to accomplish polarization.
Polishing (Fiber Optic): The act of smoothing ends of fibers to an "optically smooth" finish, generally using abrasives. Optically smooth surfaces allow maximum transmission of light between fibers at connections, and minimize coupling loss.
Polyethylene: A thermoplastic with toughness, flexibility at low temperatures, resistance to chemicals and moisture, processability, and relatively low price.
Polytetrafluoroethylene (PTFE): This is the most thermally stable and chemically resistant of all carbonaceous insulating compounds. It is unaffected by sunlight, moisture, and practically all chemicals. Temperature range is -90° to 250° C and electrical properties are very constant over the temperature range and a wide range of frequencies.
Potting: The sealing of a cable termination or other part with a liquid composition that hardens into an elastomer or solid plastic material.
Pre-Tinned Solder Cup: Solder cups whose inner surfaces have been pre-coated a small amount of tin lead solder.
Press-fit Contact: An electrical contact that can be pressed into a hole in an insulator, printed board (with or without plated-through holes), or a metal plate.
Printed Circuit: This term is in common use with at least two meanings: 1) A generic term to describe a printed board produced by any of a number of techniques used to fabricate electrical interconnect systems. 2) A circuit obtained by printing and comprising printed components.
Quadrax: An abbreviation of quadraxial, a concentric cable having a center conductor, two intermediate conductors, and an outer shield, all separated by insulation.
Quick Disconnect: A type of connector shell that permits rapid locking and unlocking of two connector halves.
Radio Frequency (RF): The frequency range is technically broad, from about 25 kHz to 100 GHz, but the term is normally used to define the low range band of frequencies used for broadcast radio signals (including broadcast television) and extends from about 500 kHz to a few hundred megahertz.
Rear Mounted: A connector is rear mounted when it is insta1led from the inside of a box onto a panel. It can only be removed from the inside of the equipment. See Back Mounted.
Receptacle: Usually the fixed or stationary half of a two-piece multiple contact connector. Also the connector half usually mounted on a panel and containing socket contacts.
Reflection Loss (Fiber Optic): Energy reflected back toward a cable source. The reflections occur because the signal strikes a non-uniformity in the shield or conductor.
Resistance: A measure of the difficulty in moving electrical current through a medium when voltage is applied. It is expressed in ohms.
Return Loss: A measure of the percentage of the incident power that is reflected back down the transmission line. Return loss is the percentage reflected power expressed in dB notation.
RG/U: Abbreviation for Radio Guide, Universal. RG is the military designation for coaxial cable.
RMS or rms: Abbreviation for root-mean-square. When the term is applied to alternating voltage and current, it means the effective value; i.e., it produces the same heating effect as a direct current or voltage of the same magnitude. It is also a means of expressing a-c voltage in terms of d-c, usually approximately 70% of the a-c peak voltage.
Rubber: An elastic (natural or synthetic) material (e.g. silicone) used to provide waterproofing or moisture resistance. See O-ring.
Sheath: The outer covering or jacket of a multi-conductor cable.
Shield: In cables, a metallic layer placed around a conductor or group of conductors to prevent electrostatic or electromagnetic interference between the enclosed wire and external fields. See Braid.
Shield Effectiveness: The ability of a shield to screen out undesirable signals and prevent leakage.
SI: The standard international system of metric units of measurement.
Silica Glass (Fiber Optic): Glass made mostly from silica (silicon dioxide, SiO2) used to make fibers.
Simplex Cable (Fiber Optic): A single fiber cable.
Single Mode Fiber (Fiber Optic): Abbreviated as SMF, a fiber having a small core diameter (approximately 9 microns) with a cladding having a refractive index very close to that of the core. Will transmit light in a single mode that enters at a narrow angle but will transmit over very wide bandwidths.
SMPTE: An acronym for "Society of Motion Picture & Television Engineers," a USA standards organization.
Socket Contact: A female contact designed to mate with a male contact. It is normally connected to the "live" side of a circuit.
Solder: A metal or metal alloy, usually having a low melting point, used to join other metals having higher melting points than the solder.
Solder Cup: A tubular end of a terminal in which a conductor is inserted prior to being soldered. It is also the hollow cylinder at the rear of a solder contact where a wire is inserted and soldered in place.
Solid Conductor: A conductor consisting of a single wire.
Spring Finger Action: Design of a contact as used in a printed circuit connector or a socket contact, permitting easy, stress-free spring action to provide contact pressure and/or retention.
Step Index Fiber (Fiber Optic): A multimode fiber consisting of a core of uniform refractive index surrounded by cladding of a slightly lower refractive index. Accepts light rays over wider angle, but has smaller bandwidth than single mode fiber. See also Graded Index Fiber and Single Mode Fiber.
Stranded Conductor: A conductor composed of groups of wires twisted together.
Surface Mounting: The electrical connection of components to the surface of a conductive pattern without utilizing component holes in a circuit board.
Temperature Rating: The maximum temperature at which a material may be used in continuous operation without a loss of its basic properties.
Temper: (1)The hardness and strength produced by mechanical or thermal treatment or both. It is characterized by a certain structure, mechanical properties or reduction in area during cold working. (2)A measurement of the degree of hardness or lack of ductility in a metal.
Threaded Coupling: A means of coupling mating connectors by engaging threads in a coupling ring with threads on a receptacle shell.
Tight Buffer (Fiber Optic): A material surrounding a fiber in a cable, holding it firmly in place.
Tinning: Coating of a terminal, lead or conductive pattern with tin or solder alloy to improve or maintain solderability or to aid in the soldering operation.
Total Internal Reflection (Fiber Optic): The phenomenon of light rays reflecting at the core-clad boundary of an optical fiber, allowing transmission along the length of the fiber. It occurs when the angle of incidence is lower than the critical angle.
Transceiver: A device that combines both a transmitter and a receiver.
Transmission: The transfer of electric energy from one location to another through conductors or by radiation or induction fields.
Triaxial: Refers to a three conductor cable with one conductor in the center, a second circular conductor shield concentric with the first, and the third circular conductor shield insulated from and concentric with the first and second, usually with insulation.
Tubing: A tube of extruded non-supported material.
Twisted Pair: A pair of wires twisted together, usually standard low-speed communications wire cables.
UG: The two-letter designation that precedes the number on connectors for coaxial cable. It is an abbreviation for Universal Government.
UL: Mark of approval issued by Underwriters Laboratories, Inc.
Ultraviolet (Fiber Optic): A range of electromagnetic waves in the non-visible spectrum, with wavelengths from 10 to 400 nm (shorter than visible light).
UPC (Fiber Optic): A term describing a specific fiber optic contact polishing protocol (process), yielding improved return loss.
Volt (V): Unit of electromotive force. It is the difference of potential required to make a current of one ampere flow through a resistance of one ohm.
Voltage: The term most often used in place of electromotive force, potential, potential difference or voltage drop, to designate electric pressure that exists between two points and is capable of producing a flow of current when a closed circuit is connected between the two points.
Voltage Breakdown: A test to determine maximum voltage across an insulated wire before electrical current leakage occurs through the insulation.
Voltage Rating: The highest voltage that may be continuously applied to a wire or cord in conformance with standards or specifications.
Voltage Standing Wave Ratio (VSWR): The ratio of the maximum effective voltage to the minimum effective voltage measured along the length of a mismatched radio frequency transmission line.
Watt (W): Unit of power or work done at rate of one joule per second or rate of work represented by current of one ampere under a pressure of one volt (volt-ampere).
Wavelength: The distance measured in the direction of propagation of a repetitive electrical pulse or waveform between two successive points that are characterized by the same phase of vibration (one cycle).
Wiping Action: The action that occurs when contacts are mated with a sliding action. Wiping has the effect of removing small amounts of contamination from the contact surfaces, thus establishing better conductivity.