Simultaneous calibration of a large number of thermocouples

The objective of this paper is to analyze major error sources in the process of simultaneous calibration of a large number of thermocouples (TCs). The main reason for the occurrence of additional error sources when a large number of TCs are simultaneously calibrated is due to additional inhomogeneity effects and characteristics of a particular measuring setup. The need for such calibrations is due to the fact that, often, a large number of relatively low-cost but traceably calibrated TCs are needed for monitoring purposes and measurements of temperature profiles in applications, such as evaluation of temperature and humidity chambers, wind channels, tunnel furnaces in steel plants, etc. The fact is that the overall uncertainty attributed to each particular TC during simultaneous calibration exceeds the uncertainty assigned to a TC during a calibration process of a single TC. Nevertheless, in most cases, the proposed solution is highly acceptable, especially in the area of testing, due to a significant decrease of calibration costs yet still meeting testing requirements.