RTD Sensors - PT100

Temperature Sensor Basics

Resistance Temperature Detectors (RTDs)

have a linear increase in resistance as temperature rises. RTDs come in 2-wire, 3-wire 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 thermocouples include: they are less linear and accurate than RTDs, a matching extension wire is needed, and thermocouples are sensitive to electrical noise.

AutomationDirect offers a variety of RTD probes and sensors:

RTD Probes

• with Connection Head
• Spring-loaded with Connection Head
• with Hex Nipple
• Spring-loaded with Hex Nipple
• with Attached Plug
• with Lead Wire Transition
• M12 Cable Connection
• Sanitary RTD Connection
• Heat trace with connection head
• Flange mount
• Cuttable length
• Melt bolt

RTD Sensors