Metallivastuslämpömittarit

Metallivastuslämpömittarit, often referred to as Resistance Temperature Detectors (RTDs), are a type of temperature-measuring device that utilizes the principle that the electrical resistance of a metal changes with temperature. As the temperature of the metal increases, its electrical resistance also increases. RTDs are known for their accuracy, stability, and wide temperature range.

The most common RTD element is made of platinum, due to its resistance being highly proportional to temperature and its resistance to oxidation. Other metals like nickel and copper are also used, but platinum offers superior performance. The basic construction of an RTD involves a fine wire of the chosen metal wound around a ceramic or glass core. This assembly is then protected by a sheath, typically made of stainless steel, to withstand environmental conditions.

When used in a circuit, a small, constant current is passed through the RTD element. The voltage drop across the RTD is then measured. By applying Ohm's law (V=IR), the resistance can be calculated. This resistance value is then correlated to a specific temperature using a predefined calibration curve or formula. RTDs are widely employed in industrial applications, scientific research, and laboratory settings where precise temperature monitoring is crucial, such as in chemical processing, power generation, and food production. Their reliability and long-term stability make them a preferred choice over thermocouples in many situations.