Aerospace Glossary Letter S Continued

S Continued

Span – In flat cables, the distance from the reference edge of the first conductor to the reference edge of the last conductor (in cables having flat conductors), or the distance between the centers of the first and last conductors (in cables having round conductors), expressed in inches or centimeters.
Spark Test – A test designed to locate imperfections (usually pin-holes) in the insulation of a wire or cable by application of a voltage for a very short period of time while the wire is being drawn through the electrode field.
Specific Gravity – The ratio of the density (mass per unit volume) of a material to that of water.
Spiral Wrap – The helical wrap of a material over a core.
Splice – A mechanical device or fusion process that permanently bonds two fibers together without a connector producing extremely low loss.
STP – Shield Twisted Pair cable.
Stability Factor – The difference between the percentage power factor at 80 volts/mil and at 40 volts/mil measured on wire immersed in water at 75 C for a specific time.
Static Condition – Used to denote the environmental conditions of an installed cable rather than the conditions existing during cable installation.
Stranded Conductor – A conductor composed of single solid wires twisted together, either singly or in groups.
Strip Force – The force required to remove a small section of insulating material from the conductor it covers.
Structure Return Loss (SRL) – Expresses the amount of signal lost in negative terms, and occurs when signals reflect back to points of transmission.
Suggested Working Voltage – AC voltage that can be applied between adjacent conductors.
Surface Resistivity – The resistance of a material between two opposite sides of a unit square of its surface. It is usually expressed in ohms.
Surge – A temporary, large increase in the voltage or current in an electric circuit or cable.
Sweep Test – A method to determine the frequency response of a cable, by generating an RF voltage whose frequency is varied at a rapid constant rate over a given range.