Patent ID: 7752891
Filing Date: 2010-07-13
Classification: G01M,Y10T

Abstract:
1. A method for manufacturing a hollow body including at least one of testing tightness of the hollow body and a change in a volume of the hollow body caused by pressure stress applied to walls of the hollow body, the method comprising the steps of: exposing said hollow body to one of a positive or negative pressure difference between an internal pressure of the hollow body and a pressure outside the hollow body, said exposing including pre-charging a pre-chamber with a predetermined volume to predetermined pressure and then discharging said pre-charged pre-chamber to the hollow body, thereby establishing equalized pressure in said pre-chamber and said hollow body; tapping off the pressure prevailing in the hollow body at a first point in time; tapping off the pressure prevailing in the hollow body from said hollow body at a second point in time; generating an electrical signal in dependence upon a pressure difference between values of the prevailing pressures at said first and second points in time; determining at least one of the tightness and change in volume of the hollow body from the generated signal.