Resistance Temperature Detectors (RTDs) are more reliable and ?accurate than thermocouples. They have a sensing element which often ?contains a grid of conductive film or a coil of w

Resistance Temperature Detectors (RTDs) are more reliable and  accurate than thermocouples. They have a sensing element which often  contains a grid of conductive film or a coil of wire.

Materials to be used as sensing elements and wire materials for RTDs to select the suitable detector 

The materials to be used as sensing elements for Resistance  Temperature Detectors (RTDs) include platinum, nickel, copper, and iron.  Platinum sensing elements can be exposed to temperatures of up to 1200 0F.  Materials such as nickel/iron alloy, copper, and nickel can also be  used. However, they cannot be exposed to higher temperatures like  platinum. Their useful temperatures are often lower than platinum  temperatures.

Materials such as tinned copper, nickel-plated copper, nickel alloys,  and nickel can be used as wire materials. The maximum usage temperature  for tinned copper is 221 0F, silver-plated copper 400 0F, nickel-plated copper 500 0F, and solid nickel wire 1200 0F (Desmarais et al., 2021).

How thermocouples types and temperature ranges are involved

Thermocouples have two electrical conductors made of different  materials connected at one end. Various types of thermocouples include  Types E, J, K, N, T, R, S, and B. Types E, J, K, N, and T are referred  to as base metal thermocouples. They are made of silicon, iron,  aluminum, nickel, and copper. Thermocouple types have their preferred  usage conditions. For example, the temperature limit for Type J  thermocouples is 1000 0F (Desmarais et al., 2021). Bare type T thermocouples have a limit of 700 0F. The temperature range for type S and R thermocouples is 1000 to 2700 0F, while the temperature range for type B thermocouples is 1000 to 3100 0F. Various types of thermocouples have different applications based on their temperature ranges.

References

Desmarais, R., & Breuer, J. (2021). How to select and use the right temperature sensor. SENSORS-PETERBOROUGH-, 18(1), 24-36.