7 Methods of conversion7.1 Conversion of air performance test data7.1.1 GeneralThe test results can only be compared directly with the guaranteed values when, during the acceptance tests, the measurements of the performance of the fan are taken under the specified conditions (see ISO 5801).In most fan tests it is not possible to exactly reproduce and maintain the operating and/or driving conditions on the test airway as specified in the operating conditions.Calculations may be required and the converted results may then be compared with the specified values.