RTD Input - Temperature Transmitters convert Platinum, Copper, Nickel RTD or resistance sensor input signals to 4-20mA or 0-10V DC outputs for interfacing to controllers or other instrumentation.

RTD Input Temperature Transmitters - Continued

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Resistance temperature detectors (RTDs) are sensors that measure temperature by measuring the electrical resistance of a material. RTDs are made from materials such as platinum, copper, or nickel, and the resistance of the material changes with temperature in a predictable way. RTDs are known for their high accuracy and stability, making them a popular choice for temperature measurement in a variety of applications.

Platinum RTDs are particularly popular because platinum has a very high resistance temperature coefficient, meaning that the resistance of the platinum element changes significantly with temperature. This results in a very high sensitivity to temperature changes, which allows platinum RTDs to achieve high accuracy and precision in temperature measurement.

RTDs are generally more accurate and stable than thermocouples, which are another type of temperature sensor that work by measuring the voltage generated by the junction of two different metals. However, thermocouples have a higher operating temperature range than RTDs and can be used in applications where RTDs would be damaged by the high temperatures.

In summary, RTDs are a good choice for temperature measurement when high accuracy and stability are required, particularly in applications where the temperature is below about 800°C. Thermocouples are a good choice for applications where the temperature is higher, but they are generally not as accurate as RTDs.

Top Considerations When Selecting RTD Types

  1. The RTDs Temperature Coefficient of Resistance (TCR)
  2. Its relative sensitivity
  3. Its accuracy and repeatability
  4. Interchangeability
  5. Stability and drift characteristics
  6. Insulation resistance
  7. Its response time
  8. Its packaging and the thermal transfer mechanism between the sensed material and the sensor element.
  9. The negative effects of corrosion and contamination
  10. Shock and vibration
  11. Self-heating
  12. Meter loading
  13. And in some cases, even thermoelectric effects

Learn more about temperature measurement in this Technical Paper