3M low-range free fatty acid monitoring strips provide a quick measurement of free fatty acid content up to 2.5%. The color marks on the test strip indicate the percentage of fatty acids.

This process is suitable for large fast-food chains that always use the same oil and only one fryer. Standard free fatty acid monitoring, which measures free fatty acid content up to 7%, is also available.

The 3M LRSM strip is dipped into the fat at operating temperature. By counting the number of yellow bands, the stage of fat breakdown is indirectly determined. As the fat breaks down, the concentration of free fatty acids increases, causing a color change in more bands on the 3M LRSM strip. A blue band will completely change to yellow at a specific concentration of free fatty acids.