If you use thermocouples in high-temperature applications, you’re aware of the issues thermocouple drift can cause. Thermocouples drift. It’s not a question of IF, it’s a question of WHEN. And thermocouple drift costs processors time and money in processing errors, waste, downtime, and lost production.
Thermocouple drift occurs due to metallurgical changes of the metal alloy elements over the extended use of the sensor. Thermocouples can drift by as much as several degrees per year.
New insulation materials have allowed manufacturers to produce thermocouple assemblies that delay the onset of drift. Plus, developments in instrument technology now include drift detection circuits and algorithms. Honeywell offers temperature controllers with built-in thermocouple drift detection and alarm functions.
This video talks about thermocouple drift, and explains how Honeywell digital controllers detects it.
- Honeywell universal digital controller models UDC2500, UDC3200, and UDC3500 with Thermocouple Health Monitoring
- Honeywell HC900 hybrid control system (process automation controller) with modular I/O
If you’re interested in other lessons on instrument configuration and setup, visit Lesman’s YouTube channel for more video demonstrations, or add a comment below and tell me what setup or configuration instructions you’d like me to demonstrate.
#1 by Matt Johnson on September 20, 2014 - 3:33 pm
Thank you for this helpful article on thermocouple drift and the informative video on how to detect it.
#2 by Andrew on April 20, 2016 - 12:56 am
The construction of a thermocouple consists of two different metals joined together to make a continuous circuit. When a temperature difference takes place, between any 2 points in the circuit, an electromotive force (voltage) occurs.