Hydrogen Analysis

Luvak Inc. has experience with determination of Hydrogen content

Method: Inert Gas Fusion Equipment: Leco RH-404 Hydrogen Analyzer Reference: ASTM E 1447

A weighed sample is melted in a graphite crucible in a stream of high purity argon. Molecular hydrogen is released from the sample and is separated from any carbon monoxide and nitrogen liberated from the sample. A thermal conductivity cell determines the hydrogen content from which the weight % of hydrogen in the sample is calculated. Calibration is verified with NIST or NIST traceable standard reference materials of known hydrogen content.

Method: Vacuum Hot Extraction Equipment: NRC Model 917 Reference: ASTM E 146

A weighed sample is introduced through a vacuum lock into a molybdenum crucible in a vacuum line system. Prior to analysis, the sample is cleaned with ether and allowed to dry prior to weighing to remove any surface contamination. Heat is then applied to the crucible through an induction coil, the sample and crucible are heated to a point just below the melting point of the sample and with the aid of high speed diffusion pumps, and hydrogen is extracted from the sample and collected within the system. The amount of hydrogen present is then measured using a McLeod gauge and results are reported in parts per million by weight. Calibration is verified with NIST or NIST traceable standard reference materials of known hydrogen content.

The vacuum hot extraction technique offers the advantage of a fixed calibration which can provide good precision for determination of hydrogen content from 0.1 ppm to 1%. The fixed calibration also allows for accurate hydrogen determination at lower sample mass. Since the sample is not consumed, vacuum hot extraction provides opportunity for retrieval of samples for additional analyses.