Resistanssilämpömittari

Resistanssilämpömittari, often abbreviated as RTD (Resistance Temperature Detector), is a type of temperature sensor that works by measuring the change in electrical resistance of a specific material with temperature. As the temperature of the RTD element increases, its electrical resistance also increases. This predictable relationship allows for the accurate determination of temperature.

The most common material used in RTDs is platinum, due to its stable and linear resistance-temperature characteristics over a wide range. Other materials like nickel and copper can also be used, but platinum offers superior accuracy and durability. An RTD typically consists of a fine wire wound around a ceramic or glass core, or a thin film deposited on a substrate. These elements are then enclosed in a protective sheath.

To measure the temperature, a small, constant current is passed through the RTD element. A voltmeter then measures the voltage drop across the element. Using Ohm's law (V=IR), the resistance can be calculated, and consequently, the temperature can be determined based on the known resistance-temperature curve of the specific RTD material. RTDs are favored for their accuracy, stability, and repeatability, making them suitable for applications requiring precise temperature monitoring in industrial processes, scientific research, and laboratory settings.