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Thermocouple Wire Differences

Wednesday, June 24, 2020

One of Allied Wire & Cable's primary goals is to provide our customers with the right supplies that fit their needs. However, AWC has a long list of products and an even longer list of subcategories with their own individual specifications. Understandably, this large inventory of different products can be overwhelming and we want our customers to understand the differences in certain specifications. For today, this blog will be about the Thermocouple wire and its different variations as well as the specifications

As it says in the product catalog, Allied Wire & Cable's Thermocouple Wire is used in the construction of a thermocouple temperature sensor or the sensing point (or probe part) of the thermocouple and can perform even in exceptionally high service temperatures. There are multiple types and grades of thermocouple wire, with each type having a specific combination of metal alloys. Each thermocouple wire specification is identified with a specific letter and each one has its own function. 


PVC THERMOCOUPLE WIRE: The PVC Thermocouple wire is part of Allied's wide-range of temperature measuring wire. PVC thermocouple wire possesses a flame retardant PVC jacket, providing good dielectric mechanical strength, that helps make a premier high-temperature wire. Our supply of PVC Thermocouple Wire-Single Pair 105°C and PVC Multi-Pair Thermocouple Wire 105°C are stocked in an array of configurations to help meet various requirements for thermocouple wire. 

TYPE E THERMOCOUPLE WIRE: Type E thermocouple wire is composed of a positive chrome wire and a negative constantan wire. Type E thermocouple works well for cryogenic and chemical applications. Our TYPE E Thermocouple has a temperature range of -454 to 1600F (-270 to 870C)

TYPE K THERMOCOUPLE WIRE: The Type K is a general-purpose, inexpensive thermocouple with great temperature precision. Type K is composed of a positive Chromel wire and a negative Alumel wire. The thermocouple also has a wide temperature range, with a peak continuous temperature of around 1,100C. It is the most universal type of thermocouple because of its low-cost, accurate, dependable, and wide temperature range characteristics. The type K is administered in nuclear applications because of its relative radiation stability and has a temperature range of -454 to 2,300F (-270 to 1260C)  

TYPE J THERMOCOUPLE WIRE: The Type J thermocouple is universally adopted in spite of having a shorter temperature range and a precise lifespan at higher temperatures compared to the Type K. The main application for Type J thermocouple is for older equipment that does not work with modern thermocouples but may also be used for other laboratory and industrial equipment. However, the Type J is identical to the Type K in terms of budget and dependability. Type J thermocouple wire is composed of a negative constantan wire and a positive iron wire and has a wide temperature range, a great voltage output, and is low cost.

TYPE N THERMOCOUPLE WIRE: Type N is designed to be an improved type K and is intended for mainly the same applications as type K. The type N thermocouple wire is composed of a positive Nicrosil wire and a negative Nisil wire. It is very stable and resistant to high-temperature oxidation and works well for high-temperature measurements at a lesser cost than the platinum types of thermocouples. It also has the same efficiency and temperature limits as the Type K but has better repeatability between 572F to 932F (300C to 500C) compared to the type K. 

TYPE R THERMOCOUPLE WIRE: The Type R thermocouple wire is composed of a positive Platinum-Rhodium wire and a negative Platinum wire. It is resistant to corrosion and intended for high-temperature applications. This cable is also administered in lower temperature applications because of its high accuracy and stability and has a temperature range of -58 to 2700F (-50 to 1480C).

TYPE T THERMOCOUPLE WIRE: The Type T thermocouple wire is used for applications such as electrical generators and has a positive Copper wire and a negative Constantan wire. This long-lasting thermocouple is commonly used in utmostly low-temperature applications such as cryogenics or super-low freezers. As well as being regularly used for sub-zero temperature monitoring this cable is also administered in laboratory environments and has exceptional temperature repeatability between –380F to 392F (–200C to 200C). 


As you can see, there are many different variations of the Allied Wire & Cable’s “Thermocouple Wire” and it can be overwhelming to see this list. But, believe it or not, the list does not actually end there. There are multiple versions of the Thermocouple wires that each have their own specifications. Luckily, these variations are pretty easy to understand and are all very similar to each other, with the exception of the I.D. Letter. For simplicity's sake, we are going to call these variations the Type X thermocouple wire. Each standard thermocouple wire has around ten versions of a Type X wire with different specifications. Three of the cables are either single paired or multi paired with PVC. The other seven are paired with a different type of insulation that aid in its temperature rating, with the wires ranging from 204C to 1204C. For more information on the specs of the cables, follow the link below. 


We hope you found this blog helpful in your understanding and selection of Thermocouple wires.

If you’re unsure about what cable you’ll need in order to meet the needs of your application, consult with one of Allied’s knowledgeable sales reps by submitting an RFQ. Visit our website to learn more about High-Temperature Wires.



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