Choose the Right Temperature Sensor
Temperature Sensor Overviews - How They Work:Thermocouples - Thermocouples are the most commonly used temperature sensors. A thermocouple is created when two dissimilar metals touch and the contact point produces a small open-circuit voltage as a function of temperature. This thermoelectric voltage is known as Seebeck voltage and can be used to calculate temperature. Learn More RTD - Resistance temperature detectors (RTDs) are made of coils or films of metals (usually platinum). When heated, the resistance of the metal increases; when cooled, the resistance decreases. Passing current through an RTD generates a voltage across the RTD. By measuring this voltage, you determine its resistance and, thus, its temperature. Learn More Thermistor - A thermistor is a piece of semiconductor made from metal oxides; pressed into a small bead, disk, wafer, or other shape; sintered at high temperatures; and finally coated with epoxy or glass. Like RTDs, you can pass a current through a thermistor to read the voltage across the thermistor and determine its temperature. However, unlike RTDs, thermistors have a higher resistance (anywhere from 2,000 Ω to 10,000 Ω and a much higher sensitivity (~200 Ω/°C). But thermistors are generally only used up to the 300 °C temperature range. Learn More
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