Resistance Temperature Detectors

Introduction

The Platinum Resistance Thermometer (PRT) is a high accuracy Resistance Thermometer Detector (RTD) commonly ued in industrial temperature measurement. These devices are also commonly described by their nominal resistance value in ohms at 0°C, e.g. Pt100, Pt500, Pt1000.

Universal Thermosensors most commonly manufacture resistance thermometers with a platinum element and all the styles referred to on this web site have been designed for various configurations of a platinum element with a resistance of 100/500/1000 Ohms at 0°C and a temperature coefficient a of 0.00385/°C with an accuracy conforming to BS EN 60751:1996 Class A or B (replaced BS 1904:1984). Closer tolerance elements are available for some applications on request.


Resistance elements with different characteristics (i.e. JIS, MIL, SAMA ) are also available in some cases. Please check with UNIVERSAL'S technical department before ordering.

For a wide range of low to medium temperature applications the traditional ceramic bulb resistance element, housing fine gauge platinum wires, has been replaced with ceramic thin film element devices, offering smaller package sizes, good environmental performance and lower cost. Up to 200°C PRTs offer roughly 2 to 3 times closer accuracy tolerances compared with a type 'K' thermocouple, class for class, and also offer greater repeatability and stability. RTDs also connect with low cost copper extension wire, with no requirement for a cold junction compensation.


Universal Thermosensors have been using thin film technology since its introduction, and now produce RTDs making full use of the benefits these elements provide to produce innovative designs, often in small diameters with short immersion lengths.

One of the main advantages of the thin film technology over the conventional glass or ceramic element construction is the ability to withstand very high vibration environments, for example those often experienced in test cells in engine manufacturing industries.


We would be happy to discuss any application regarding the use of RTDs either for new or existing applications, or as an alternative to small diameter thermocouples.