Reducing Thermowell Conduction Errors in Gas Pipeline Temperature Measurement

Abstract

It is well known that conventional thermowells will thermally “couple” with the vessel in which they are mounted resulting in an error in the temperature measurement. Conduction error, commonly called immersion error, is present whenever a temperature gradient exists between the vessel or pipe the thermowell is installed into, and the substance being measured. Sources of conduction error in gas temperature measurement and methods of reducing it, specifically the use of finned thermowells, are discussed.