Notes provide thermocouple basics
Martin Rowe, Senior Technical Editor -- Test & Measurement World, 12/1/2006
Thermocouples are the most popular temperature sensors in use today. They are used in applications ranging from bench measurements with a digital multimeter (DMM) to industrial measurement and control applications with dataloggers and temperature controllers. Two application notes from Dataforth help you understand how thermocouples work, and they provide tips on how to reduce measurement errors.
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Thermocouples connect to data-acquisition systems through a thermal block that includes cold-junction compensation. |
Application note 107, “Practical Thermocouple Temperature Measurements” (www.dataforth.com/catalog/pdf/an107.pdf), explains the different types of thermocouples, their temperature ranges, linearization, and measurement equipment. Graphs show you how thermocouple voltages are nonlinear with respect to temperature.
Note 107 also covers why instruments need cold-junction compensation and how they apply it. You'll get tips on how to use thermocouples and minimize measurement errors, such as those caused by ground loops. Finally, the note provides links to several sources for further reading.
Both application notes mention Dataforth products, but only as examples of technical concepts.
