NACE Standard TM03741 addresses only the screening of CaSO4 and CaCO3 scale inhibitors. By contrast, this standard test method is intended to provide the user with a relative and quantitative measure of the ability of scale inhibitors to prevent (1) the formation and (2) the precipitation of solid BaSO4 or SrSO4, or both, which are necessary and critical stages in scale deposition. The laboratory screening procedure described in this standard may not allow for the simulation of all oilfield system variables. It must be regarded only as a starting point in the evaluation of scale inhibitors. The procedure standardizes the collection of screening test results to facilitate discussion of the results by interested parties. No attempt has been made to define the test brine composition, test temperature, or test duration. Users of this standard must agree on these and other critical parameters to facilitate comparison of test results.