A thermocouple is an electrical device consisting of two dissimilar metal wires forming an electrical measurement junction at one end and a two-terminal connection at the other end called the reference point. It produces a temperature-dependent voltage as a result of the thermoelectric effect, and this voltage is proportional to the difference in temperature between the measurement junction and the reference point. Therefore, an additional temperature sensor is required to measure the reference point temperature and is usually a silicon-based sensor, RTD, or thermistor. This reference point sensor is also known as the cold junction compensation point.

In contrast to most other methods of temperature measurement, thermocouples are self-powered and require no external form of excitation. They are inexpensive, interchangeable, and usually supplied with standard connectors. Because thermocouples are so basic, they have several advantages: they can measure extreme temperatures of –270°C to +1800°C, are robust, can be very small, can have a very fast response time, and have no self-heating.

Thermocouple Measurement

Thermocouple Measurement

Application Note: Temperature is easily the most commonly measured physical parameter. A number of transducers serve temperature measuring needs and each has advantages and considerations.

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Thermocouple Linearization When Using the AD8494/AD8495/AD8496/AD8497

Thermocouple Linearization

Application Note: The AD8494/AD8495/AD8496/AD8497 thermocouple amplifiers provide a simple, low cost solution for measuring thermocouple temperatures.

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Thermocouple Signal Conditioning Using the AD594/AD595

Thermocouple Signal Conditioning

Application Note: Using the AD594/AD595 we review thermocouple fundamentals and illustrate circuit designs for thermocouple signal conditioning

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Thermocouple 101

Thermocouple 101 is an 8 video whiteboard series covering a wide range of Thermocouple related topics.

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Signal Chains


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Reference Designs

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