The insulating envelope of myelin that surrounds the core of a nerve fiber or axon and facilitates the transmission of nerve impulses. In the peripheral nervous system, the sheath is formed from the cell membrane of the Schwann cell and, in the central nervous system, from oligodendrocytes. Also called medullary sheath
Of a communications or power cable, the outer covering or coverings of tough material, often plastic, that is resistant to environmental hazards such as abrasion, liquid intrusion, solar radiation, etc , and is used to protect cable component(s) such as optical fibers or metallic conductors that transport the signal or power Note: There may be more than one sheath surrounding a given cable For example, some cable designs use an inner sheath surrounded by metallic armor, over which is an outer sheath Synonym jacket
The material, usually an extruded plastic or elastomer, applied outer-most to a wire or cable Very often referred to as a jacket, but usually consists of a shield and jacket for outside plant telephone cables
THE TUBULAR ENCLOSURE OF AN RTD OR THERMOCOUPLE USUALLY MADE OF INLESS STEEL OR OTHER CORROSION RESISTANCE METAL (INCONEL, MONEL) NORMAL DIAMETERS (OD) ARE 3/16" TO 3/8" WITH 1/4" BEING THE MOST USED LENGTHS VARY FROM 2" TO 48" DEPENDING ON THE APPLICATION