Gravimetry

Presentation of study

To ensure the future traceability of concentration measurements for the various components of natural gas, LNE is developing reference materials in the form of reference gas mixtures with 11 components, prepared using the gravimetric method.

To calculate the concentrations and associated uncertainties for a gravimetric reference gas mixture, the purity of the gases used to make the gas mixture must be determined.

The purpose of this study is therefore to identify and quantify major impurities present in the pure gas compounds used in making gravimetric reference "natural gas" mixtures. This is done by using a gas chromatograph with a pulse discharge helium ionization detector (PDHID).

This method will enable the laboratory to determine the concentrations of the 11 components of its gravimetric reference gas mixtures with great accuracy.

Resources

LNE is equipped with a gas chromatograph with a PDHID.

Work in progress

The study is being performed as follows:

• First stage: certain pure gas compounds, such as methane, are injected into the gas chromatograph in order to identify major impurities.
• Second stage: the concentration of each impurity is determined after calibrating the gas chromatograph with reference gas mixtures prepared by LNE using the gravimetric method

Contact

Christophe Sutour