An inorganic compound of hydrogenA natural gas element used in non-destructive testing, hydrogen is a chemical element with the symbol "H" and atomic number 1. It is the lightest and most abun… and oxygen. Used in non-destructive testingRefers to a range of techniques and methods used to assess the integrity, quality, and properties of materials, components, or structures without causing damage… as a penetrant and as a medium for testing.