Total Acid Number (TAN)

Total Acid Number (TAN) is a measurement that indicates the amount of acidic substances in a lubricant or oil. It quantifies the oil’s acidity level, which can increase over time due to oxidation, contamination, or chemical reactions. A higher TAN suggests more acids are present, potentially leading to corrosion, wear, and damage to machinery. Monitoring TAN helps evaluate oil condition, determine when it needs replacement, and prevent equipment failures. It is expressed in units called milligrams of potassium hydroxide (mg KOH) per gram of oil. Regular testing of TAN is essential for maintaining optimal machine performance and longevity.