Temperature measurements (PT 100 elements and bimetallic thermometers) in process piping often takes place in thermowells. However, both NORSOK and Shell DEP's are open for using surface measurement ("skin" measurement), and from time to time I have seen the surface measurement method being used. It is my impression that the experience is good - and at least these installations does not have problems with broken thermowells in for example natural gas lines.
In the February issue of "International Oil & Gas Engineer" there was an article saying that in gas metering the surface measurements were often as accurate as using thermowell measurements.
Can anybody give me some further references (books, articles, etc.) where the two methods of temperature measurement are compared, both in terms of accuracy and in terms of response to changes?
In the February issue of "International Oil & Gas Engineer" there was an article saying that in gas metering the surface measurements were often as accurate as using thermowell measurements.
Can anybody give me some further references (books, articles, etc.) where the two methods of temperature measurement are compared, both in terms of accuracy and in terms of response to changes?