Gas analyser apparatus and method
AssigneeMIRO Analytical AG
InventorsOleg Aseev, Herbert Looser
Life of this patent
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Abstract
A gas analyser apparatus using laser absorption spectroscopy includes at least two lasers, preferably up to five, six or seven lasers, and a laser housing (6). The at least two lasers are mounted in the laser housing. The laser housing (6) includes a monolithic main body defining an interior space for receiving the lasers and a lid for sealingly closing the main body. The laser housing is arranged within an outer housing of the gas analyser apparatus. This gas analyser can be assembled and adjusted in a quite simple way.
Claims30
A gas analyzer apparatus using laser absorption spectroscopy wherein the gas analyser comprises at least two lasers, and a laser housing, wherein the at least two lasers (66) are mounted in the laser housing and wherein the laser housing comprises a monolithic main body defining an interior space for receiving the lasers and a lid for sealingly closing the main body, wherein the laser housing is arranged within an outer housing of the gas analyser apparatus.
The gas analyzer apparatus according to claim wherein collimating or focusing optics are mounted to the main body and are assigned to each through-opening and wherein the optics are adjustable in x-y-z directions.
A method for starting-up a gas analyzer apparatus using laser absorption spectroscopy, especially a gas analyser apparatus based on direct laser absorption spectroscopy, the method comprising the following steps
- calculating a good guess for a “bare power laser” using set-up parameters,
- normalizing a detected spectrum,
- calculating an experimental absorbance,
- transforming a time based absorbance to a equi spaced, frequency based absorbance,
- calculating a derivative of frequency equi-spaced absorbance,
- finding a maximum in cross correlation of experimental data with a “HITRAN” spectrum or based on a custom made database in order to find the absolute frequencies,
- preforming a nonlinear regression on the detected spectrum with the found absolute frequencies as the starting parameters, thereby obtaining new start values for subsequent nonlinear regressions.
A gas analyzer apparatus using laser absorption spectroscopy wherein the gas analyser comprises a multipass cell with a cell body, a front mirror holder and a back mirror holder, wherein the cell body has a main tube with an interior space for receiving gas to be analysed and wherein the cell body has an gas inlet for leading the gas into this interior space and an gas outlet for leading the gas out of this interior space, wherein the main tube is made of glass, characterized in that the gas inlet and the gas outlet are made of glass.
A gas analyzer apparatus using laser absorption spectroscopy wherein the gas analyser comprises an optical sample cell with a cell body, a front mirror holder and a back mirror holder, wherein the back mirror holder comprises a back mirror and adjustment means for adjusting the back mirror, characterized in that the adjustment means comprises a lever arm which is rotatable around a longitudinal middle axis of the optical sample cell by movement of a micro-screw which can be moved in a direction perpendicular to the longitudinal middle axis of the optical sample cell.
Dependencies are inferred from the claim text.