RI 9312 - An Improved Method For Preparing Gravimetric Standard Gas Mixtures of Helium-4 in Nitrogen
- Organization:
- The National Institute for Occupational Safety and Health (NIOSH)
- Pages:
- 12
- File Size:
- 434 KB
- Publication Date:
- Jan 1, 1990
Abstract
An improved method for preparing gravimetric standard gas mixtures of helium-4 in nitrogen has been developed by the U.S. Bureau of Mines. A single-pan 12-kg analytical balance that has a sensitivity of 3 mg is used to prepare the mixture. The balance will accommodate a cylinder having a volume of approximately 4 L that weighs approximately 5 kg. The method has been improved to a precision of ±O.04 pct by performing four successive dilutions, by improved handling of gases in the manifold, and by using an improved analytical method to select high-purity gases.
Citation
APA: (1990) RI 9312 - An Improved Method For Preparing Gravimetric Standard Gas Mixtures of Helium-4 in Nitrogen
MLA: RI 9312 - An Improved Method For Preparing Gravimetric Standard Gas Mixtures of Helium-4 in Nitrogen. The National Institute for Occupational Safety and Health (NIOSH), 1990.