Glass container wall thickness inspection apparatus.

摘要

An object, for example a glass bottle, has a dimension, for example its wall thickness, inspected by use of a capacitance sensor. A periodic voltage is generated by a measuring oscillator whose frequency is representative of the sensed capacitance, and a voltage representative of the dimension of the object is generated by use of a phase locked loop having a voltage controlled reference oscillator which is forced to operate at the same frequency as the measuring oscillator. The voltage input to the reference oscillator is thus representative of the dimension of the object.