Rationale

This ballot addresses conflicting guidance in D5453-24 sections 13.5 and 14.1. Specifically, 14.1 indicates that the density of the test sample is calculated from a “mass of sample (with a precision of ± 0.01 mg) where the sample mass is derived from the sample’s volume obtained “with Class A volume precision”. And 13.5 indicates that the sample mass is determined “… by performing a gravimetric weighing of the test sample into a Class A volumetric flask …” A lab determining density as per 14.1 may use a Class A 25 mL volumetric flask having a tolerance ± 0.03 mL as per ASTM E288 Table 1, Requirements for Volumetric Flasks (see below). And if, for example, the test sample density is in the range of 0.7 gm/mL to 0.8 gm/mL, the ± 0.03 mL volume tolerance equates to a mass tolerance of ± 0.021 gm to ± 0.024 gm (0.7 gm/mL x 0.03 to 0.8 gm/mL x 0.03 mL = 0.021 gm to 0.024 gm) or ± 21 mg to ± 24 mg. Moreover, the guidance in 14.1 may cause the lab to unnecessarily use a balance that determines mass to the hundred thousandths of a gram (a mass having at least 5 significant figures). Such a determination would result in the above density calculation with 5 significant figures or more in the numerator, only 4 significant figures in the denominator, and thus only 4 significant figures in the quotient.