System and method of eliminating interference for impurities measurement in noble gases
AssigneePanalytique Inc.
InventorsYves Gamache, André Fortier
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Abstract
The invention provides a system and a method of eliminating interference for impurities measurement in noble gases based on emission spectroscopy which provide very stable, sensitive and interference free results. The method mainly relies on the use of a combination of particularly designed means serially connected for cancelling interferences and proper means for correcting linearity issues. The proposed method is particularly advantageous since it offers long-term stability while providing very accurate and reliable results, even at sub-ppb and up to 10,000 ppm levels, whatever the surrounding conditions and the additional impurities that could be present in the gas under analysis.
Claims33
A method for impurities measurement in noble gases, comprising steps of:
- a) providing a gas sample having at least one interfering impurity and at least one impurity to be measured therein, wherein at least one impurity to be measured is an impurity other than H2O;
- b) providing at least one trapping means to define an impurities trap having an inlet and an outlet, said at least one trapping means being adapted to trap at least one interfering impurity without affecting the at least one impurity to be measured;
- c) introducing the gas sample at the inlet of the impurities trap for removing said at least one interfering impurity;
- d) reducing the effect of variations in moisture content within the gas sample on measurement of a first impurity to be measured, wherein said first impurity is an impurity other than H2O, by adding moisture to the gas sample;
- e) introducing the moisturized gas sample obtained in step (d) in a plasma cell of a plasma emission system;
- f) collecting an emission light generated by the plasma cell at a specific emission wavelength not subjected to spectral interference for providing an emission signal representative of a concentration within the sample gas of at least said first impurity to be measured;
- and
- g) measuring the concentration of at least said first impurity to be measured according to the emission signal provided in step (f).
A system for impurities measurement in a gas sample having at least one interfering impurity and at least one impurity to be measured therein, wherein at least one impurity to be measured is an impurity other than H2O, said system comprising:
- at least one trapping means to define an impurities trap having an inlet and an outlet, said at least one trapping means being adapted to trap at least one interfering impurity without affecting the at least one impurity to be measured;
- means for reducing the effect of variations in moisture content within the gas sample on measurement of a first impurity to be measured, wherein said first impurity is an impurity other than H2O, by adding moisture to the gas sample;
- a plasma cell of a plasma emission system serially connected to said reducing means for generating an emission light representative of a concentration within the gas sample of at least said first impurity to be measured;
- and
- processing means operatively connected to the emission cell for processing said emission light and providing the concentration of at least said first impurity to be measured.
Dependencies are inferred from the claim text.