Master Catalog Page 285 Thermocouple Cable

Alpha Wire www.alphawire.com 1-800-52 ALPHA Specifications subject to change. For complete specifications and availability, visit www.alphawire.com. 285 Manhattan Thermocouple Cable Temperature Measurement and Control The measurement of temperature is one of the most vital functions in the control of manufacturing and processing operations. As demands for greater quality, reliability, and economy increase, the demands for more precise measurement and control increase. Newer and more sophisticated electronic circuitry is employed creating stringent demands on the wire and cable used to sense and transmit temperature measurements. To meet these ever-increasing demands, Alpha has a full line of thermocouple- grade wire and thermocouple extension wire and cable. The Thermocouple At the heart of all temperature measurements is the thermocouple. Although involving very complex design parameters, the fundamental concept of all thermocouples is the same. Two wires of dissimilar metal are joined together at one end. An increase in temperature creates an electromotive force (EMF) or signal, which is transmitted through these wires to a monitoring device which "reads" this signal and displays it on a previously calibrated meter or digital device. The monitoring device is usually at a location some distance away from the actual thermocouple. To connect the thermocouple to the monitor requires wire or cable (for multiple thermocouple installations) that will maintain the integrity of the temperature-EMF signal generated by the primary wires in the thermocouple. Conductor Materials The range and accuracy of temperature measurement are dependent on the conductor materials employed. Pairs of various metal alloys will react differently with changes in temperature. The following tables give the temperature range and tolerances for the most popular alloy combinations. All Alpha thermocouple wire and cable is tested and calibrated to the standard limits of error as indicated. Where situations require closer tolerances, wire and cable calibrated to the special error limits is available under special order. Limits of Error for Thermocouple Grade ANSI Type Material Temperature Range (C) Standard Limits () Special Limits () J Iron/Constantan 0 to 277 2.22C 1.11C 277 to 760 0.75% 0.375% K Chromel/Alumel 0 to 277 2.22C 1.11C 277 to 1260 0.75% 0.375% T Copper/Constantan -184 to -101 - 1% -101 to -59 2% 1% -59 to 93 0.83C 0.42C 93 to 371 0.75% 0.375% E Chromel/Constantan 0 to 316 1.67C 1.25C 316 to 871 0.5% 0.375% R Platinum 13% Rhodium/ Platinum 0 to 538 1.39C - 538 to 1482 0.25% - S Platinum 10% Rhodium/ Platinum 0 to 538 1.39C - 538 to 1482 0.25% -

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