Two sensor layouts are available basically for the thickness measurement. One sensor is used for the reference measurement on a roller. The product runs over a roller which is used as a basis for the zero point. The subsequent measurement on the product is set off against the zero point and output as a thickness.
In the thickness measurement with two sensors the product runs between two sensors, one above, one below the material. The difference between the two sensor values gives the thickness. The advantage of this measuring set-up is that the product can move vertically to the direction of travel without causing measuring errors. Air-cooled OPTImess sensors are available for measuring warm materials. Traversing thickness measuring systems are available in addition to the stationary thickness measurement with separate measuring tracks.