I am preparing for MSA studies on an instrument that measures density and specific gravity. The question was asked whether we need to do two studies, one for density and one for specific gravity. The instrument prints both results for each test. Some feel that it is not necessary to run separate tests when specific gravity can be calculated once density is known. I would like to purchase separate standards and run separate tests, at least for the initial set of studies. I need to justify allocating the resources to do that. I am also flexible enough that I will adjust my thinking if there is justification for relying on the instrument's conversion between the two.