18 April 2019

RTD advantages and disadvantages

RTD stands for resistance temperature detectors, it is used to measure temperature. RTD is generally high repeatability, good precision, Accurate, and repeatability compared to a thermocouple. So here this post gives information about the advantages and disadvantages of RTD to better understand this topic.

Advantages of RTD:
  • Very stable output
  • Most accurate
  • Linear and predictable
  • High accuracy
  • High repeatability
  • Good precision
  • Low Drift 
  • More linearity compare to a thermocouple
  • No special wire required for installation, easily install and update
  • It is available for in wide range
  • It can be used to measure differential temperature
  • No necessity of temperature compensation
  • Stability maintained over a long period of time
  • They are suitable for remote indication
  • Easy to verify and recalibrate
  • RTD does not require a special extension cable
Disadvantages of RTD:
  • High initial cost
  • Low sensitivity 
  • It requires a more complex measurement circuit
  • Large bulb size
  • Low absolute resistance
  • Current source needed
  • Less rugged in a high vibration environment
  • A bridge circuit is needed with power supply
  • Shock and vibrations affect the reading
  • Point sensing is not possible
  • A circuit is little more complicated as it 34/4 wire measurement
  • Costlier as compared to other sensors like thermocouples
  • Slower response time than a thermocouple
  • More limited temperature range
  • Possibility of self-healing
  • Power supply failure can cause an erroneous reading
  • It can be avoided in industries for ranges above 650 deg. C
  • The RTD requires more complex measurement circuit