1.1 This part of ISO/TR 7066 describes the procedures to be open channels, and of assessing he uncertainty associated with such calibrations. Procedures are also given for estimation of the uncertainty arising in measurements obtained with the use of the resultant graph, ad for calculation of the uncertainty in the mean of a number of measurements of the same flowrate. 1.2 Only linear relationships are considered in this part of ISO/TR 7066; the uncertainty is non-linear relationships forms the subject of ISO/TR 7066-2. This part of ISO/TR 7066 is applicable, therefore, only if a) the relationships between the variables is itself linear. Or One or both variables can be transformed in such a manner as to create a linear relationship between the, as for instance by the use of logarithms, Or The total range can be subdivided I such a way that within each subdivision the relationship between the two variables can be regarded as being linear; and if. b) systematic deviations from the fitted line are negligible compare with uncertainty associated with the individual observations forming the graph. NOTE--- Examples of the application of contained in this part of ISO/TR 7066 are given in annexes B and C.