Extension Cables and
A thermocouple is a self-powered device that are used to measure wide range of temperature. It consists of two different conductors that contact each other at one or more spots where temperature difference is experienced. Then, two conductors create voltage that are converted to temperature readings in the control box. Thermocouple utilizes ‘extension cables’ to measure temperature from its body to the control box, where the measurements are calculated. Since extension cables are made of the same exact material as thermocouples, they yield accurate reading results. However, extension cables are fairly expensive and new cables were invented to compensate the cost; they are called
compensating cables’. Compensating cables are made of materials that easily and quickly transfer temperatures. Copper, iron and constantan are main materials used to make compensating cable. Though there are some limitations on accuracy, the range of errors is definitely not that significant. Places (such as plants) that require very accurate temperature readings tend to use extension cable; while others look for compensating cables for cost efficiencies.
Symbols for Extension & Compensating Wire
Shield N: None | S: Copper Tape | SB : Copper Braided | AMS : Aluminum Mylar Tape Shield | SWA: Steel Wire armoring
SQ : mm²