1. n. [Drilling Fluids]
A procedure for determining magnesium ion (Mg+2) concentration in a water-base drilling fluid based upon analyses for both calcium and total hardness. The standard test has been proscribed by API. Magnesium ion (Mg+2) concentration is calculated by subtracting calcium (Ca+2) analysis results from total hardness analysis results.
See related terms: buffered solution, calcium test, EDTA, hard water, hardness ion, total hardness test
