During field testing (service life), materials are exposed to aggressive atmospheres typically containing sulfur dioxides, nitrogen oxides, etc .

These gases in conjunction with metallic materials are responsible for corrosive effects.
Classic example: Rust in case of iron and steel. That effect reduces the physical lifetime of materials.

The objective of mixed flowing gas testing is to confirm that tested materials do not corrode within predefined time limit.

Single gas tests / Flowing mixed gas tests

Typically, corrosive gas testing is carried out as single gas testing or 4-component mixed flowing gas testing.