Description and Uncertainty Analysis of NISTs 20 Liter Hydrocarbon Liquid Flow Standard (20 L HLFS) | NIST

The National Institute of Standards and Technology (NIST) uses a bi-directional piston prover as its primary standard for measuring hydrocarbon liquid flows ranging from 1.86 × 10 m/s (0.3 gpm) to 2.6 × 10 m/s (40 gpm). An uncertainty analysis is presented that shows that the uncertainty over this flow range is 0.074 % (k = 2). As a verification of the uncertainty analysis NIST shows comparison results between its new 20 L piston prover standard and its other hydrocarbon liquid standards and its water flow standard using a dual rotor turbine meter as the transfer standard. Keyword: NIST liquid hydrocarbon flow standard, piston prover, water draw procedure, liquid flow calibration, uncertainty analysis, 20 L HLFS