Temperature difference measurement with using two RTD sensors as example of evaluating uncertainty of a vector output quantity

. The evaluation of results in the case of indirect multi-parameter measurements is presented. A theoretical basis for determining the estimates of values, the uncertainties and the correlation coefficients of indirectly obtained multi-measurand is explained in detail. The example of a difference and an average of two-temperature indirect measurement is given with the use of two RTDs. Such sensors are used in the laboratory and industrial temperature control systems. The uncertainty of measurements depends on the errors of two RTDs and the structure of signal conditioning circuit.