ISO 7537:1997 PDF

Overview - ISO 7537:1997 (acid number, semi-micro colour‑indicator titration)

ISO 7537:1997 specifies a semi‑micro colour‑indicator titration method to determine the acid number of petroleum products and lubricants. The method is designed for small sample volumes and for materials soluble in or suspendable in a toluene / propan‑2‑ol solvent system containing a small amount of water. It is intended for acids (and salts that hydrolyse) with dissociation or hydrolysis constants larger than 10‑9 and is especially useful when sample quantity is limited.