What is a Resistance Temperature Detector (RTD)?

As the name implies, they are sensors used to measure temperature by correlating the resistance of the RTD element with temperature. RTD element is made from a pure material which has a predictable change in resistance as the temperature changes; it is this predictable change that is used to determine temperature.

Common Resistance Materials for RTDs:
    Platinum (most popular and accurate)
    Nickel
    Copper

Wire wound elements RTD
The standard RTD elements used in Ametek’s sensor assemblies are made of 99.99% pure platinum wire wound about a ceramic or glass core and hermetically sealed within a ceramic or glass capsule. 

Thin film RTD
Thin film RTD’s are made up of a thin layer of a base metal embedded into a ceramic substrate and trimmed to produce the desired resistance value. This method allows for the production of small, fast response, accurate sensors.