The standards of IMGC and NIST for small gas flows were compared at the IMGC laboratory. The IMGC standard is a recently developed primary flow meter that extracts a large piston out of a temperature-controlled chamber. Controlling the piston's speed holds the pressure in the chamber constant. The NIST standard is a recently developed transfer standard that was calibrated against two primary standards at NIST. The first NIST primary standard extracts a large piston out of an oil-filled chamber in which a metal bellows is suspended. Controlling the piston's speed holds the pressure in the bellows constant. The second NIST primary is a static gravimetry method. The results of the comparison include 49 nitrogen flow rates from 0.22 micromol/s to 770 micromol/s. For all but one of the comparisons, the agreement between IMGC and NIST is better than 0.06%
NIST-IMGC comparison of gas flows below one litre per minute
2003
Abstract
The standards of IMGC and NIST for small gas flows were compared at the IMGC laboratory. The IMGC standard is a recently developed primary flow meter that extracts a large piston out of a temperature-controlled chamber. Controlling the piston's speed holds the pressure in the chamber constant. The NIST standard is a recently developed transfer standard that was calibrated against two primary standards at NIST. The first NIST primary standard extracts a large piston out of an oil-filled chamber in which a metal bellows is suspended. Controlling the piston's speed holds the pressure in the bellows constant. The second NIST primary is a static gravimetry method. The results of the comparison include 49 nitrogen flow rates from 0.22 micromol/s to 770 micromol/s. For all but one of the comparisons, the agreement between IMGC and NIST is better than 0.06%I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
