The optical jet speed cross profile measurement allows problems such as fiber orientation disturbances or longitudinal streaks in multi-ply paper machines to be narrowed down to a single ply.
With the aid of the measurement, quick identification of the cause and elimination of the problem can be carried out. To achieve this, the optical jet speed measuring unit with sensor head on a measuring cross beam is positioned above the forming board. The measuring device traverses over the stock jet in a measuring carriage, creating an optical jet speed cross profile. Positioning of the sensor head over the stock jet takes place via a freely programmable motor control. The speed cross profile can be determined with any resolution (minimum: 30 mm). The optical measurement procedure determines only the jet surface speed, usually ca. 5% less than the average jet speed. An optional calibration is thus necessary for absolute values.
The jet speed cross profile measurement is used for determining the jet speed cross profile with multi-ply machines.