PT100 Bearing Sensor
RTD (PT100) Sensors
| Temperature Sensor Basics
Resistance Temperature Detectors (RTDs) have a linear increase in resistance as temperature rises. RTDs come in 2-,3- or 4-wire versions. A 2-wire RTD signal is affected by the distance to the controller. 3-wire or 4-wire RTDs can compensate for line losses.
Thermocouples have two dissimilar metal wires joined at the hot junction. As temperature changes, a millivolt signal is read at the cold junction. The most common types of temperature thermocouples are type j thermocouples and type k thermocouples. Advantages of thermocouple sensors include: low cost, small size, wider temperature ranges and faster response than RTDs. The disadvantages of using temperature thermocouples include: they are less linear and accurate than RTDs, a matching extension wire is needed, and thermocouples are sensitive to electrical noise.