Patent Document ID: 20130209218
Application ID: 13704594
Patent Flag: 0

Claim One:
1. A turbomachine ( 100 ) comprising: a chamber ( 101 ) having an inlet ( 102 ) and an outlet ( 103 ) for fluid to be moved, an impeller ( 104 ) placed in the chamber for moving the fluid, equipment ( 105 - 107 ) for measuring first process quantities related to the turbomachine, and a processor ( 108 ) for calculating an estimate for a second process quantity related to the turbomachine on the basis of measured values of the first process quantities and a reference table of interrelations between process quantities prevailing in reference inlet conditions which correspond to a predefined inlet fluid temperature, a pre-defined inlet fluid pressure, and predefined fluid properties at the inlet, characterized in that the reference table and the measured values of the first process quantities represent such a set of data values that the estimate is obtainable on the basis of different sub-sets of the set of data values, and the processor is arranged to give, in the calculation of the estimate, more weight to a first sub-set of the set of data values which has a smaller error estimate than to a second sub-set of the set of data values which has a greater error estimate in order to increase the accuracy of the estimate, the error estimate related to each sub-set being proportional to a scalar product of a vector of squares of sensitivities of the estimate with respect to the data values of that sub-set and a vector of variances of the data values of that sub-set.