platinavastuslämpömittarit

Platinavastuslämpömittarit, often abbreviated as RTDs (Resistance Temperature Detectors), are a type of temperature-measuring device that utilizes the principle that the electrical resistance of a pure metal changes in a predictable way with temperature. Platinum is the most common metal used due to its stable and reproducible resistance-temperature relationship, its resistance to corrosion, and its wide operating temperature range.

The basic construction of a platinavastuslämpömittari involves a fine platinum wire wound around a ceramic or glass core. This coil is then protected by an outer sheath, typically made of stainless steel, to prevent mechanical damage and environmental contamination. The resistance of the platinum wire is measured by passing a small, known current through it and measuring the voltage drop across it. According to Ohm's Law, resistance is directly proportional to voltage and inversely proportional to current. By calibrating the RTD, this resistance value can be accurately translated into a temperature reading.

Platinavastuslämpömittarit are known for their high accuracy, excellent stability, and good repeatability. They are generally more accurate than thermocouples over a wide temperature range, particularly at lower temperatures. However, they are typically slower to respond to temperature changes compared to thermocouples and can be more fragile and expensive. Common RTD configurations include Pt100 (100 ohms resistance at 0°C) and Pt1000 (1000 ohms resistance at 0°C), with Pt100 being the most widely used standard. They find applications in various industries, including chemical processing, food and beverage, pharmaceuticals, and laboratory instrumentation where precise temperature measurement is critical.