Active Standard: D7759 - 12a
First, a recommendation was made to omit the definition of source rod from the Terminology section to the Apparatus section and expand upon a more generic definition of a Probe that can contain a radioactive source, a detector, or both. Second, Sections 12.8 and 13.4 pertain to the calibration blocks that have non-zero water mass per unit volumes assigned to them, where allowing a 5% tolerance makes sense. For an intrinsic standard like the zero water content standard that is often used in gauge water system calibrations, a 5% tolerance does not make sense, since 5% of zero is still zero. Sections 12.8 and 13.4, therefore, were modified to account for this inconsistency.
Keywordscalibration; calibration block; calibration constants; calibration curve; calibration standard; curve fit; gauge; in-place density; nuclear gauge; uncertainty; verification; water content; water mass per unit volume;