Patent ID: 7498817

Claim:
A method of nondestructive noncontact tightness testing of inner structure of articles based on gas discharge visualization, comprising the steps of: providing a film for imaging on a dielectric plate and an electrode, said dielectric plate disposed on said electrode; polarizing said dielectric plate by applying a series of high voltages pulses across said dielectric to provide a preliminary polarized dielectric plate; after said polarizing step, arranging an article to be tested having a multi-layer casing including an outer metallic layer on said film; subjecting the article to a high voltage pulsed electric field by applying a high voltage electrical pulse between said electrode and the said outer metallic layer and said electrode, wherein said pulsed electric field is combined with an electric field associated with said preliminary polarized dielectric plate triggers a gas discharge process, and obtaining an image on said film of an interior structure of said article based on said discharge process.