Designing with temperature sensors, part three: RTDs

摘要

The temperature coefficient of an RTD (resistance-temperature-detector) element is positive. Most stable, linear, and repeat-able RTDs are of platinum-metal construction. You can use the constant 0.00385Ω/Ω/℃ to approximate the resistance change over temperature for the platinum RTD element. In contrast, the NTC (negative-temperature-coemcient) thermistor has a negative change with increasing temperature. See a comparison of resistance and temperature performance for RTD sensors and NTC thermistors in the Web version of this article at www.edn.com/111117bb.