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RS PRO Thermocouple Selection Guide - 24 Pages

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RS PRO Thermocouple Selection Guide

Catalog excerpts

Thermocouple Selection Guide uk.rs-online.com (UK) www.rs-components.com (International)

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Thermocouple Thermometry - At a Glance SELECTING SENSOR CABLES: GUIDE TO INSULATION & COVERING Which insulation Material? Screened or unscreened? With long cable runs, the cable may need to be screened and earthed at one end (at the instrument) to minimise noise pick-up (interference) on the measuring circuit. Alternative types of screened cable construction are available and these include the use of copper or mylar screening. Twisted pair configurations are offered and these can incorporate screening as required. Tolerance classes for thermocouples to IEC 60584-1 Fe-Con (J)    Class 1    -...

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Comparison of Sensor Types Comments and values shown in this chart are generalised and nominal. They are not intended to be definitive but are stated for general guidance.

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Different Thermocouple Junctions Sheathed Thermocouples – Measuring Junctions Many alternative sheath materials are used to protect thermoelements, three alternative tip configurations are usually offered: An exposed (measuring) junction is recommended for the measurement of flowing or static non-corrosive gas temperature when the greatest sensitivity and quickest response is required. An insulated junction is more suitable for corrosive media although the thermal response is slower. In some applications where more than one thermocouple connects to the associated instrumentation, insulation...

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Different Thermocouple Types The materials are made according to internationally accepted standards as laid down in IEC 584 1,2 which is based on the international Practical Temperature scale ITS 90. Operating temperature maxima are dependent on the conductor thickness of the thermoelements. The thermocouple types can be subdivided in 2 groups, base metal and rare (noble) metal: -200°C up to 1200°C – These thermocouples use base metals Type K – Chromel-Alumel: The best known and dominant thermocouple belonging to the group chromium-nickel aluminium is type K. Its temperature range is...

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Immersion or Surface Temperature Measurement Surface Temperature Measurement Thermocouple assemblies are “tip” sensing devices which lends them to both surface and immersion applications depending on their construction. However, immersion types must be used carefully to avoid errors due to stem conduction; this is heat flow to or from the sheath and into or away from the process which can result in a high or low reading respectively. A general rule is to immerse into the medium to a minimum of 4 times the outside diameter of the sheath; no quantitative data applies but care must be...

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Comparison of Sheath Materials Sheath Material * Tradenames Sheath materials range from mild and stainless steels to refractory oxides (ceramics, so called) and a variety of exotic materials including rare metals. The choice of sheath must take account of operating temperature, media characteristics, durability and other considerations including the material relationship to the type of sensor.

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Choosing between a Thermocouple and RTD Sensor Thermocouples comprise a thermoelement which is a junction of two specifield, dissimilar alloys and a suitable two wire extension lead. The junction is a short circuit only, the EMF is generated in the temperature gradient between the hot junction and the ‘cold’ or reference junction. This characteristic is reasonably stable and repeatable and allows for a family of alternative thermocouple types (e.g. J,K,T,N) to be used. The alternative characteristic. types are defined by the nature of the alloys used in the thermoelements and each type...

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Advantages of Mineral Insulated Thermocouples M.I. (Mineral Insulated) cable is used to insulate thermocouple wires from one another and from the metal sheath that surrounds them. MI Cable has two (or four when duplex) thermocouple wires running down the middle of the tube. The tube is then filled with magnesium oxide powder and compacted to ensure the wires are properly insulated and separated. MI cable helps to protect the thermocouple wire from corrosion and electrical interference. Long stable life Small size Rapid response Great mechanical strength Water, oil & gas tight Ease of...

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Mineral Insulated Thermocouples B Plain Pot with Tails Termination Threaded Pot with Tails Termination

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Fabricated and Specialist Thermocouples Image This is just a small selection of Fabricated and Specialist Thermocouples offered by RS / Allied

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Fabricated and Specialist Thermocouples Washer Thermocouple Nozzle Thermocouple Leaf Thermocouple This is just a small selection of Fabricated and Specialist Thermocouples offered by RS / Allied Temperature Range RS Order Allied Code Code

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Fabricated and Specialist Thermocouples Silicone Rubber Patch Thermocouple This is just a small selection of Fabricated and Specialist Thermocouples offered by RS / Allied

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PVC Extension Lead with Miniature Connectors PVC Extension Lead with Standard Connectors Glassfibre Extension Lead with Miniature Connectors This is just a small selection of extension leads offered by RS / Allied

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Melt Bolt Thermocouple Twist Melt Bolt Thermocouple with Standard Thermocouple Plug 1/2"UNF-20 Melt Bolt Thermocouple with Type 'J' Thermocouple Plug This is just a small selection of melt bolts offered by RS / Allied

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PFA Exposed Junction Thermocouples Type J PFA Exposed Junction with Miniature Plug BType T PFA Exposed Junction with Miniature Plug This is just a small selection of exposed junctions offered by RS / Allied

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PTFE Exposed Junction Thermocouples BType T PTFE Exposed Junction with Miniature Plug This is just a small selection of exposed junctions offered by RS / Allied

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Fine Gauge PFA Exposed Junction Thermocouples Type T PFA Fine Gauge Exposed Junction with Miniature Plug D Type K PFA Fine Gauge Exposed Junction with Miniature Plug This is just a small selection of exposed junctions offered by RS / Allied

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