Rieter

The mechanical principle

Index

Fig. 134 – Mechanical measuring system

This is the most common system for deriving a measured value. Usually, two material-forwarding rollers are used. One of these rollers must be movable (up and down) relative to the other. The relative movement, corresponding to the volume of the material passing through (a, Fig. 134) gives the instantaneous value required for the regulation operation.

The rollers can be smooth or grooved, b and c. The latter arrangement prevents lateral escape of the fibers and thus gives more precise measurement. However, it must be so designed and must operate in such a manner that the fibers are not crushed at the roller edges.

The advantage of the mechanical principle lies in its insensitivity to variations in the characteristics of the raw material, with the possible exception of bulk.