Applying the Appropriate Temperature Sensor Device

Each type of industrial measurement device has functions unique to how they are constructed and where they will be used, allowing for the best application possible

In the previous article we discussed how to choose an industrial measurement device based on their general specs. In this article we will delve a bit deeper to identify where RTDs, thermocouples and thermistors can be used. After, all there’s a right tool for every job and when it comes to industrial thermometers, it is important to match the right device to the application to ensure their performance and accuracy in temperature measurement.

Since Temp-Pro works with clients across multiple industries, we are privy to the unique profile of each device and are available to support your custom design needs—whether you are an aftermarket service provider or an OEM. Again, it is hard to make a blanket statement on which temperature measurement device is better for an application unless we can learn more about its dynamics, but generally speaking, here are some essential points to consider for each:

RTDs – As an industrial temperature device, RTDs are considered to have great stability in measurement. Also, RTDs are highly accurate and can be reliable in measuring heat levels as high as 650°C. Unfortunately, RTDs are known to produce lead resistance error when using long cables to connect. Another consideration is that RTDs may not be the most stable in environments that produce high vibration levels—largely due to their increased size, which is susceptible to such physical forces. RTDs are made of metal (platinum, nickel or copper) and can be produced in various sizes and configurations.

Thermocouples – When measuring higher ranges of temperature, Thermocouples are the winner in temperature measurement devices, thanks to their ability to measure up to 1,750°C (RTDs can only measure up to 650°C and thermistors up to 130°C). While they are relatively inexpensive to produce, due care must be applied in ensuring that cost is not the only defining factor for selecting this type of industrial thermometer. Faster response is another advantage of thermocouples, along with their self-powered nature and durability in the harshest of industrial environments.

Thermistors – These rugged and highly-sensitive industrial thermometers are much more affordable than RTDs and even thermocouples—but measure a narrower temperature range and are non-linear, which can require fine calibration. Still, thermistors heavy-duty nature also makes them hermetically sealed and can be mounted on the surface of your industrial equipment. Thermistors are usually made of ceramic materials or a polymer, limiting the temperature range to a maximum of 130°C. Size also defines a thermistor’s resistance and can be miniature in size. Also, in the absence of a transmitter, you can connect it to a longer cable without any issues.

The application of each of these temperature measuring devices can also be influenced by a variety of factors. With this in mind, a combination of RTDs, thermocouples and thermistors can be found in many of Temp-Pro’s customers equipment. Temperature ranges are often the first defining factor, but external forces can also influence the decision to select one over the other. After all, we are a custom-design temperature measurement device manufacturer and can support any industry as long as we can understand the thermal dynamics.

Don’t hesitate to tap into Temp-Pro’s proven knowledge and effective track-record experience. Let us know how we can help and we will be ready to support your temperature measurement needs with over 40 years of expertise to ensure your success.