What Does Sulfuric Acid Spot Test Mean?
A sulfuric acid spot test is an inspection procedure that involves applying a single drop of a reagent on a metal's surface to determine the presence of sulfuric acid and corrosion.
Generally the corrosion rate increases with higher concentrations of sulfuric acid. Pitting corrosion and its corrosion products (e.g., rust) are the two most prominent identifiers on a metal's surface in the presence of sulfuric acid.
Corrosionpedia Explains Sulfuric Acid Spot Test
Sulfuric acid is a well-known contributor to corrosion on metallic surfaces. Acidic corrosion occurs in metals with high salinity and low oxygen levels. It occurs gradually by wearing away the material. Sulfuric acid generally comes in contact with metallic objects via industrial air, water or toxic chemicals in the area.
The relationship between the sulfuric acid's concentration and the corrosive behavior can be examined empirically by using extrapolation methods that examine the internal surface of a metallic object such as a pipeline. The overall process is to:
- Collect surface morphology samples
- Examine the sample with an optical microscope
- Examine the sample with a scanning electron microscope
- Determine the correlation between the rate of corrosion and surface morphology