Method of testing an airbag module

Abstract

The present invention relates to a method of testing an airbag module for a vehicle and, particularly, but not exclusively, to a method of testing an airbag module for a motor vehicle such as a car. A method of testing an airbag module is provided in which said module is tested for exposure to a given fluid, for example, water. The fluid exposure test ideally comprises the step of inspecting said airbag module or a swab taken therefrom by means of Atomic Absorption Spectroscopy techniques. The present invention thereby provides a testing method sufficiently rigorous to identify fluid damage potentially suffered by a previously installed airbag module during its service life.

1 . A method of testing an airbag module comprising the step of testing said module for exposure to a given fluid.  
     
     
         2 . A method as claimed in  claim 1 , wherein said given fluid is water.  
     
     
         3 . A method as claimed in  claim 1  or  2 , wherein said fluid exposure test comprises the step of inspecting said airbag module or a swab taken therefrom by means of Atomic Absorption Spectroscopy techniques.  
     
     
         4 . A method as claimed in any preceding claim, wherein said fluid exposure test comprises the step of inspecting said airbag module or a swab taken therefrom for deposits of a metal.  
     
     
         5 . A method as claimed in  claim 4 , wherein the step of inspecting for deposits of a metal comprises the step of inspecting for cations.  
     
     
         6 . A method as claimed in  claim 4  or  5 , wherein the step of inspecting for deposits of a metal quantifies the amount of metal deposited.  
     
     
         7 . A method as claimed in  claim 6 , wherein the step of inspecting for deposits of a metal quantifies the amount of metal deposited for a given surface area of airbag module.  
     
     
         8 . A method as claimed in any of  claims 4  to  7 , wherein the step of inspecting for deposits of a metal comprises the step of taking a swab from a surface of said airbag module by applying a solvent to said surface.  
     
     
         9 . A method as claimed in  claim 8 , wherein the solvent is 5% hydrochloric acid.  
     
     
         10 . A method as claimed in  claim 8  or  9 , wherein the step of inspecting for deposits of a metal further comprises the step of agitating said swab with 1% lanthanum chloride solution.  
     
     
         11 . A method as claimed in  claim 10 , wherein the step of inspecting for deposits of a metal further comprises the step of inspecting the mixture of 1% lanthanum chloride solution and swab by means of Atomic Absorption Spectroscopy so as to determine the quantity of a deposited metal present in said mixture.  
     
     
         12 . A method as claimed in any of  claims 8  to  11 , wherein said swab is taken from a surface of said airbag module which cannot be conveniently wiped clean.  
     
     
         13 . A method as claimed in  claim 12 , wherein said surface is a surface of or adjacent a gas generator of said airbag module.  
     
     
         14 . A method as claimed in  claim 12 , wherein said surface is a surface of a reaction can of said airbag module.  
     
     
         15 . A method as claimed in any of  claims 4  to  14 , wherein the fluid exposure test comprises the further step of determining a threshold quantity of a deposited metal which, if found on said airbag module, indicates an unacceptable risk of said module having been damaged through fluid exposure.  
     
     
         16 . A method as claimed in any of  claims 4  to  15 , wherein said deposited metal is calcium or sodium.  
     
     
         17 . A method as claimed in  claim 1  or  2 , wherein said fluid exposure test comprises the step of inspecting said airbag module or a swab taken therefrom by means of Inductively Coupled Plasma, polarography or colourimetric techniques.  
     
     
         18 . A method of testing an airbag module comprising the steps of: (i) locating an airbag module which has been previously installed; (ii) establishing a set of criteria to be satisfied before said airbag module is deemed acceptable for future use; and (iii) investigating against said set of criteria so as to determine the acceptability of said airbag module for future use.  
     
     
         19 . A method as claimed in  claim 18  comprising the methods of testing an airbag module for exposure to a given fluid according to any of  claims 1  to  17 .