What is the function of a basic resistive temperature sensor (RTD)?

Material Selection: RTDs are typically made using materials that exhibit a predictable and repeatable change in resistance with temperature. Platinum is one of the most commonly used materials due to its linear resistance-temperature relationship and stable characteristics.

Resistance-Temperature Relationship: The resistance of the RTD element increases with temperature in a relatively linear manner. This relationship is characterized by the temperature coefficient of resistance (TCR), which indicates how much the resistance changes per degree Celsius.

Wiring Configuration: RTDs are connected in various configurations, with the most common being the 2-wire, 3-wire, and 4-wire configurations. The choice of configuration helps minimize the effect of lead wire resistance, which can introduce errors in the temperature measurement.

Measurement Circuit: An RTD is typically connected to a measurement circuit that provides a known current through the RTD element and measures the resulting voltage across it. Using Ohm's law (V = I * R), the resistance of the RTD can be calculated. This resistance value is then used to determine the temperature based on the RTD's known resistance-temperature characteristics.

Calibration: RTDs often require calibration to ensure accurate temperature measurements. Calibration involves comparing the measured resistance of the RTD with a known temperature and adjusting the measurement system accordingly.

Linear Response: One of the key advantages of RTDs is their linear response over a wide temperature range. This linearity simplifies the conversion of resistance values into temperature values, making RTDs a popular choice in various industrial and scientific applications.

Accuracy and Stability: RTDs are known for their high accuracy and stability over time. They are capable of providing precise temperature measurements, making them suitable for applications where accuracy is crucial.

Applications: RTDs find applications in industries such as manufacturing, process control, laboratory research, and more. They are used in scenarios where accurate and consistent temperature measurement is essential for quality control, safety, and scientific experimentation.

In summary, the function of a basic resistive temperature sensor (RTD) is to provide a reliable and linear change in electrical resistance with changes in temperature, which can then be used to accurately measure temperature in a variety of applications.