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Thermocouples are designed to provide you with reliable, accurate temperature readings. However, you might not get the results you want if you don’t choose the right type of thermocouple for your application.

There are several different types of thermocouples that you can choose from, but there is no “one-type-fits-all” solution. Instead, it’s key to find out which type of thermocouple is best suited for your applications. Let’s start with one of the most common types of thermocouples available.


The Type J variant of thermocouples is a popular general purpose sensor. They are commonly used for a wide variety of applications and are known for reliability and cost effectiveness. Type J’s are one of the nickel alloy thermocouples and is made with an iron positive leg and a constantan negative leg.

Type J thermocouples are a fairly versatile option, although it does have a smaller temperature range than Type K thermocouples, another common part option. The iron leg of the Type J thermocouple oxidizes more rapidly in sulfurous atmospheres and at temperatures over 1,000 degrees Fahrenheit, which can lead to a shorter service life at higher temperatures. The iron wire may also become fragile in freezing temperatures. However, a protection tube can be used to help keep the thermocouple clean and prolong service life, making Type J thermocouples a solid choice for general use.


Businesses invest in Type J thermocouples for good reason; they’re affordable, reliable, and fall within the temperature range of many applications. If you’re in need of quality Type J thermocouples, GeoCorp can help. We can manufacture thermocouples based around your needs, allowing you to get the thermocouples you need to succeed. 

Contact us today if you have any questions about thermocouple capabilities or design and order your own thermocouple online if you exactly what your business needs.

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