RTD Advantages and Disadvantages

Advantages of RTD :

• The response time compared to thermocouples is very fast œ in the order of fractions of a second.

• An RTD will not experience drift problems because it is not self-powered.

• Within its range it is more accurate and has higher sensitivity than a thermocouple.

• In an installation where long leads are required, the RTD does not require special extension cable.

• Unlike thermocouples, radioactive radiation (beta, gamma and neutrons) has minimal effect on RTDs since the parameter measured is resistance, not voltage.

Disadvantages of RTD :

• Because the metal used for a RTD must be in its purest form, they are much more expensive than thermocouples.

• In general, an RTD is not capable of measuring as wide a temperature range as a thermocouple.

• A power supply failure can cause erroneous readings

• Small changes in resistance are being measured, thus all connections must be tight and free of corrosion, which will create errors.

• Among the many uses in a nuclear station, RTDs can be found in the reactor area temperature measurement and fuel channel coolant temperature