Motståndstemperaturdetektorer

Motståndstemperaturdetektorer, often abbreviated as RTD, are a type of resistance thermometer used for temperature measurement. They work on the principle that the electrical resistance of a metal changes in a predictable way with its temperature. As the temperature increases, the resistance of the RTD material also increases. Conversely, as the temperature decreases, the resistance decreases.

The most common RTD material is platinum, typically denoted as Pt100, meaning it has a resistance of 100 ohms at 0 degrees Celsius. Other materials like nickel and copper are also used, but platinum offers a good combination of accuracy, stability, and a wide temperature range. RTDs are known for their excellent linearity and stability over time, making them suitable for precise industrial and scientific applications.

To measure the temperature, a small, constant current is passed through the RTD element. The voltage drop across the element is then measured, and this voltage is directly proportional to the resistance, and therefore to the temperature. RTDs are generally more accurate and stable than thermocouples but are also more expensive and have a slower response time. They are commonly found in applications requiring high accuracy, such as in food processing, pharmaceuticals, and laboratory equipment. The selection of an RTD depends on the required accuracy, temperature range, and environmental conditions.