Thermocouple basics: How to test a thermocouple loop

Q&A Temperature

I want to test a thermocouple loop by injecting a millivoltage from the field where the thermocouple terminates in its compensating cable back to a substation and a thermocouple/mA converter card with cold junction compensation. Let's say the field is 30 degrees Celsius and the substation is 10 degrees Celsius.

Expert’s answer: How to use thermocouple basics to test a thermocouple loop

Piece of cake! This goes all the way back to thermocouple basics. Come, children. Let’s have our lesson for the day.

Now, you’ll need to sum up the millivolts (mV) for each temp that you have from the sensor to the input card. The temp where you have the card will also come into play here, so get that too.


Calculation for real temperature into input card – Courtesy of SENAI

When you’ve corralled all these numbers, you’ll find that your error margin is minimal most of the time. Take a look at this handy-dandy pic to give you a better idea of what you need to do!

These guys have temp transmitters:

Check the Fluke 52 II Digital Thermometer on Amazon U.S. and Germany:

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RTD or thermistor or thermocouple?

Can thermistors detect temperature ranges up to 1600 degrees Celsius? What device can handle regular temperatures between 1100 and 1200 degrees Celsius, with excursions up to 1300 or 1400?

Multi-input temperature field converter

Is there an industrial-rated handheld that accepts TC type J, K, T, or two- or three-wire RTD inputs with either a corresponding mv output or 4-20 mA output?

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Related tags: calculation Emerson Automation Solutions Endress+Hauser Milivolts Omega SENAI Temperature temperature application Thermocouple Wika Yokogawa
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