Working of an RTD
Let us understand how an RTD works.
Diagram of an RTD
As we can see that RTD consist of a resistance elements which is fragile and therefore needs a protection which is done by providing insulation as shown by the protection tube. The insulated tube is connected to the element. Usually a metal alloy is used as protective tube because of its chemically inert behaviour.
The temperature begins from 00 C and can vary up-to the temperature range where metal shows linear change in characteristics. This range is dependant on the type of metal or resistance element being used like the range is till 6500C for platinum and can be around 3000C for nickel.
The linear characteristic of resistive element now comes into picture and the temperature coefficient of resistance can be given by
α =(R100–R0)/ (1000C.R0)
R0: resistance of the sensor at temperature 00C R100: resistance of the sensor at temperature 1000 C
This is how we can predict the temperature of device by using the linear nature of resistance element. Note that the electric current through the RTD resistance must be kept sufficiently low and constant to avoid self-heating. and also the temperature coefficient will differ from metal to metal.
Resistance Temperature Detector or RTD
In the electronics industry, we often need to deal with measuring certain quantities with precision and accuracy. One such quantity is temperature. There are different methods that can be used for measuring temperature depending on the operation range, sensitivity, frequency response, ruggedness, and other electrical parameters. In this article we will study what is an RTD, and how it works. We will also study the characteristics of an RTD.
In addition to that, we will study the advantages and disadvantages of an RTD. To study the real-life use of RTDs, we will study the applications of an RTD. In the end, some solved examples and some practice questions are provided for a better understanding of concepts. The article concludes with a summary in the end and some frequently asked questions.
Table of Content
- RTD
- Construction
- Working
- Signal Conditioning
- Mathematical Equations
- Graph
- Characteristics
- Advantages of an RTD
- Disadvantages of an RTD
- Applications of an RTD