Roll depletion monitoring device for use in particular with wrapping machines

摘要

The depletion of a roll strip material onto a relative core and rotatable about its own axis, typically as in wrapping machines, is monitored by a device comprising light-sensitive optoelectronic transducers associated directly with the roll, mounted pivotably in such a way as to advance gradually closer to the core in a substantially radial direction as the strip decoils; the transducers respond to the color presented by a given area of the roll, and will generate a signal on sensing a hue or shade that matches a previously selectable reference value.