The time zone defines the actual data frame used to draw the Campbell diagram when using only a portion of the entire analysis time.
•Auto Reliable Zone: The Auto Reliable Zone option automatically selects the zone for which linearity is guaranteed for the RPM data increase rate. If the system calculates the time differential values of the RPMs from the beginning to the end of the data and locates an increase or decrease above a certain value, then the zone of variance is excluded. If no zones of variance are found, then the system uses all of the data. The user can deselect Auto Reliable Zone to select another time zone.