US Patent 6981352 Round baler low net indication

A round baler comprising: a housing; a bale chamber receiving cut crop material; a bale forming apparatus for bale forming; a wrapping apparatus comprising a wrapping material supply roll that provides wrapping material from the supply roll to wrap about the bale, and a sensor member disposed on a pivoting sensor arm member so the sensor member abuts an outer surface of the wrapping material stored on the supply roll, and the sensor arm member moves between first position and second positions; and a low wrapping material indication system comprising a sensor disposed to sense at least the second position of the sensor arm member corresponding to a minimum thickness of the wrapping material stored on the supply roll, wherein the sensor generates a signal to indicate that the thickness of the wrapping material is at the minimum thickness when the sensor arm member is at the second position.