An RTD (resistance temperature detectors) is a device which contains an electrical resistance source which changes resistance value depending on its temperature. This change of resistance with temperature can be measured and used to determine the temperature of a process or of a material.

When to use RTD

• When accuracy and stability are a requirement of the customer’s specification.
• When accuracy must extend over a wide temperature range.
• When area, rather than point-sensing, improves control.
• When a high degree of standardisation is desirable

Advantages:

• High accuracy and can therefore be used in precision applications
• low drift with time
• Wide operating temperature range

Disadvantages:

• Are not often used above 660 C as it is difficult to keep the platinum pure