API RP 13B-2 pdf download.Recommended Practice for Field Testing of Oil-based Drilling Fluids 5.2 Apparatus a) Any density-measuring instrument having an accuracy of ± 0,01 g/cm 3 , ± 10 kg/m 3 , ± 0,1 lb/gal, or ± 0,5 lb/ft 3 . The pressurized mud balance is the instrument generally used for density determinations of pressurized drilling fluids. The pressurized...