From the course: PLC: Industrial Sensors

Unlock the full course today

Join today to access over 24,200 courses taught by industry experts.

What are RTDs?

What are RTDs? - Ladder Logic Tutorial

From the course: PLC: Industrial Sensors

Start my 1-month free trial Buy for my team

What are RTDs?

“

- [Instructor] Resistance Temperature Detectors, or RTDs, change resistance with temperature. This is based on the positive temperature coefficient of metals. That means, the electrical resistance of metals is directly proportional to temperature. The hotter they become, the larger or higher the value of their resistance. An RTD consists off a fine wire metal wrapped around non-conducting core, which is usually made of ceramic inside a protective case. Another type of RTD consists of thin film layer of metal, usually platinum, into a ceramic base. Here are examples showing the different RTDs by Omega. RTDs are sometimes called Pt100 sensors. Pt, meaning that the RTD wire is made from platinum. 100 means that at zero degrees Celsius, the sensor has a resistance of 100 Ohm. So the sensor name indicates its resistance at zero degrees Celsius. This data sheet from Omron shows Pt100 beside the sensor models, meaning they are…

Contents