1. n. [Drilling Fluids]

One of two quantitative analysis procedures for measuring aromatic content of base oils for use in oil mud as proscribed by the API. Results of the two aromatic content tests may differ because of the way the two gas-chromatography techniques separate and identify aromatics. The Institute of Petroleum (IP) instruments are more widely available than the American Society for Testing and Materials (ASTM) instruments, and the Institute of Petroleum method measures trace levels better than the more complex ASTM method.

See: aromatic hydrocarbon