NON-CONTACT THICKNESS MEASUREMENT
Thickness can be measured in different ways, depending on the measurement range (difference betwen minimum and maximum thickness).
Furthermore, clearance and vertical movement have to be taken into account. If thickness variation and object movement are small, measurement range can be small and the precision will be high.
As a rule of thumb you may say:
measurement range = vertical movement + max. thickness - min. thickness + safety.
Information requirements are the base for decision which arrangement of sensors makes sense. Objects only changing thickness in transport direction may work with one track. If the cross section changes, three or more tracks may be useful. If the complete profile needs to be known, a solution with traversing sensors is reqired.