A major step forward in Type K and N thermocouple performance for use in industrial temperature measurement.
Written by: Trevor Ford, CCPI Europe Ltd, Sheffield, United Kingdom
Part 2: Applying New Low-Drift Thermocouple Cable Technology
In Part 1, we discussed the history of mineral insulated thermocouple as the industrial temperature measurement sensor of choice and recent developments that will further enhance the temperature range and performance of type K and type N thermocouples.
In Part 2, we’ll define how you can learn more about the new low-drift mineral insulated thermocouple cable design and development as well as what makes this new design a unique solution for industrial temperature measurement and how it can be applied to the industry.
Where to find how the new design works
Technical publications and white papers written by the researcher responsible for this development, Dr. Michele Scervini and the technical director of the testing IEC 17025 accredited laboratory, Mr. Trevor Ford, have been written and published giving details of the new low drift mineral insulated cable design and the results of extensive testing that confirm the superior low drift performance of these sensors to any base metal thermocouple counterpart. (To receive more information, click here.)
Why is this new design unique?
Most developments in science, temperature measurement being no exception, are usually at the fundamentals of measurement, such as the development of the new pure element thermocouple combinations (e.g., Palladium versus Platinum or Gold versus Platinum) that have applications for increasing accuracies in the high temperature range.
However, this development as tends to be the case, will be mainly for operation in the laboratory and not for direct use for industrial applications. This low drift development in MI type K and N sensor technology, discussed previously, not only gives a major leap forward in low drift temperature measurement performance, but also provides a sensor that can increase the confidence directly in those everyday industrial temperature measurements.
This is one of the first times there has been a major increase in operation performance of an industrial contact temperature sensor that does not require the change of measurement equipment, wiring, or procedural use by the industrial users to get the dramatic increase in measurement performance. To the user, both in appearance and in operation, the new low drift MI type N and K thermocouple sensors will outwardly appear the same. In fact, the only differences the user will see is the remarkable reduction in drift and the subsequent increase in measurement performance accuracy.
New construction design for Mineral Insulated Cable (left), photo of new construction sample (right)
How to apply this new technology in industry
There are many specifications that have been developed to make sure when existing type K and N mineral insulated thermocouple designs are used that accurate or critical temperature measurements will be the result. Their drift limitations are minimized by stipulating operational times and temperatures.
Unfortunately, for this new low drift design these same specifications will result in the slow adoption of this new thermocouple design. As the new low drift thermocouple is still designated type K or type N thermocouples the specifications limitations will still apply. This will result in the user not being available to take advantage of the lower drift, higher temperature, higher stability properties of the sensor.
How do we make sure 20 years does not pass, as it did with type N thermocouple development, before the industry can take advantage of this step forward in temperature measurement technology?
The best way would be for users to write to the relevant standards committee asking them to review current standards limitations on base metal thermocouples with a view to adding this new design to the standard.