Resistance Temperature Detectors – The Working & Benefits

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Resistance temperature detector or RTD sensors are amongst the most commonly used types of temperature sensors in industrial applications. While thermistors and thermocouples are quite popular as well, but RTDs are considered better in terms of the stability they offer over a period of time and accuracy over a range of temperature. Both these factors make them a great choice for a number of industrial applications.

The basis of and RTD is that it works like a resistor that changes its value with change in temperature. Several materials have a characteristic that enables a predictable change in their resistance with change in temperature. This makes acquiring highly consistent and accurate temperature measurements quite easy. Most RTDs respond between 0.5 to 5 seconds. RTDs can be constructed using different materials, including copper, platinum, and nickel.

RTDs used in different applications may have different specifications. The Temperature coefficient of resistance and base resistance are amongst the most important specifications for RTDs. Base resistance value can vary remarkably and depend on the material; from 10 Ohms to several thousand Ohms.

The temperature coefficient of resistance is essential to the instrument that is being used in measuring temperature changes depending on the base resistance, and has nothing to do with the accuracy of the sensor.

If we consider the working of thermistors, thermocouples, and RTDs, we find that RTDs are more stable and accurate over time. RTDs are highly repeatable as well. This means that they can precisely calculate similar temperatures with minimum discrepancies, even when they are used in repeated cooling and heating cycles. On the other hand, a thermocouple is less precise and can deliver values with few discrepancies. As most of the industrial applications can do without instant responses to changes in temperature, RTDs are considered a great solution for them.

When you are considering buying RTDs, you should make sure that you factor in the accuracy offered by the sensor in different industrial settings. Is the RTD sensor you are going to buy rugged enough for the harsh environment you will be used it in?

Resistance temperature detectors are used in a variety of applications, including flame-proof and explosion-proof applications. Even with all these benefits, you still need to make sure you buy the right sensor from the right place. Consider your needs and then look for RTD sensors that fit them perfectly. You can go online look for companies that provide RTDs, thermocouples, and thermistors.