RTD and thermocouple probes are both used to measure temperature, but which one is right for your application? To help decide which will perform best based on specific needs, there are three main questions to ask.
1. What temperature range you are trying to monitor?
Generally, if measuring temperatures above 850 °C/1562 °F a thermocouple is recommended. The temperature range will vary depending on the thermocouple type, with a Type K thermocouple maxing out at 1500 °C/2732 °F. RTDs are limited when it comes to the maximum temperature of operation and can only be used for temperatures below 850 °C/1562 °F.
2. What is the required sensor accuracy?
Although RTDs cannot withstand the extreme temperatures that thermocouple can, RTDs provide faster, more accurate readings with repeatable results. RTDs produce repeatable readings, meaning that at the same temperature users will receive the same results over multiple trials.
3. What is the budget and how many are needed?
When it comes to staying within a budget and having to buy multiple probes, thermocouples are the way to go. Thermocouples are typically about three times less expensive than RTD probes, but keep in mind, thermocouples have a high drift rate which require regular adjustments and calibration.
Both RTDs and thermocouples have their advantages and disadvantages, but by answering these three questions based on the application, the decision should be straightforward.
For further assistance deciding which data logging solution best fits your application, call MadgeTech at (603) 456-2011 or email [email protected].