Definition - What does Colorimetric Analysis mean?
Colorimetric analysis refers to a quantitative technique used to measure the concentration of a given substance in a solution. This allows the quantification of substances such as water and chemicals on metallic surfaces and their corresponding contribution to corrosion rates.
This test process is particularly useful since most test substances are not readily discernible by the human eye. Colorimetric analysis is a simple mechanism to make test substances identifiable.
Corrosionpedia explains Colorimetric Analysis
For industrial applications, colorimetric analysis is performed by adding a coloring agent to the solution or metal to be inspected. The test sample will then react with the agent to give off a responsive color that correlates to a specific impurity. For example, a coloring agent may be applied to steel in an attempt to test for the presence of chlorine. If chlorine is present then the sample will turn green, otherwise no color change will be observed. This analysis can be performed on a wide range of test compounds as needed.
Ideally, in such tests the applied chemical indicates the intensity of the color by initiating a reaction. Usually the intensity that is given off is directly proportional to the concentration of the substance that is present on the metal's surface.