For the readings to be interpretable, the metals used in RTDs must have electrical resistances known to people and recorded for convenient reference. Linearity: The temperature-resistance relation in RTD is almost lineal in the sensor range, while a thermocouple has an ‘S’-type plot. Learn more about the  The many factors that can affect sensor accuracy include linearity, repeatability or stability. Both RTDs and thermocouples are sensors used to measure heat in scales such as Fahrenheit and Kelvin. RTD vs Thermocouple – What’s the difference. Resistance Temperature Detectors (RTDs) Resistance Temperature Detectors (RTDs) are sensors that measure temperature by correlating the resistance of the RTD element with temperature. RTD and Thermocouple Comparison Chart. Both can be used to measure temperatures and are suitable in a broad range of applications. RTD generally operates in the range between -200 to 600° C. Thermocouples are inexpensive, rugged, stable, operate over a wide temperature range, and are relatively linear over a wide range but deviate significantly at extremely cold or hot temperatures. 800-844-8405, ©Sure Controls. } New manufacturing techniques have improved the measurement range of RTD probes, but more than 90% of RTDs are designed for temperatures below 400°C. Comparing a 12 inch, SS sheath .25'', Type J grounded Thermocouple, with a 100 Ohm platinum RTD.00385 Alpha, prices the thermocouple at 2.5 to 3 times less than an RTD. The main benefits of an RTD sensor (Pt100, Pt1000) is the good accuracy over a fairly wide range and combined with excellent stability, this is in contrast to a thermocouple which is less accurate, less stable and can drift over time. Sometimes we might think that heat and temperature are the same. What is the difference between and a resistance temperature detector (RTD)  and a thermocouple? An RTD utilizes the change in resistance of the metal to predict the change in temperature. International delivery. RTDs vs. Thermocouples Temperature range: Thermocouples are best for working at high temperatures. Most RTDs are limited to a maximum temperature of 1000 degrees Fahrenheit. However, if we compare their performance in terms of specific criteria, we can see which is best suited for specific applications. It is not practical to compare RTDs and thermocouples generally. In contrast, certain thermocouples can be used to measure up to 2700 degrees Fahrenheit. RTD vs Thermocouple • While RTD can be easily recalibrated, thermocouples are hard to recalibrate • Thermocouple have a wide temperature range (-300 degree F to 2300 degree F) while RTD have a small temperature range (-330 degree F to 930 degree F) • Thermocouple is inexpensive while RTD are expensive initially In 1871 Sir William Siemens discovered the Resistance Temperature Detector or RTD. Thermocouples are temperature sensors that use two different metals in the sensor to produce a voltage that can be read to determine the local temperature. Furthermore, thermocouples are designed to be more durable and react faster to changes in temperature because of that same design. Thermocouples and RTDs are the two most common type of industrial temperature sensors. RTDs are temperature sensors that use the changes in the electrical resistance of metals to measure the changes in the local temperature. Most likely you’ve heard about “RTD”, “Thermocouple”, “Thermistor”, “Semiconductor” type elements and so on, which will be addressed here. Resistance/temperature relationship of metals. They are used to measure temperature for process control in automation system. 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