Patent ID: 8810794

Claim:
A device for quantifying the relative contents of two isotopes of at least one specific gaseous constituent contained in a gaseous sample from a fluid, said device comprising: a forming device configured to form a gaseous flow from the sample, said forming device comprising a separation device having a column configured to separate the gaseous sample by selective retention of the or each specific gaseous constituent to obtain a gas flow in which the or each specific gaseous constituent is separated over time at an outlet of said column; a quantifying device configured to quantify relative contents of the two isotopes of the or each specific gaseous constituent; wherein the quantifying device comprises: an optical measurement cell connected to said separation device, said optical measurement cell comprising at least two mirrors which delimit a measurement cavity, and a transporting device configured to transport the gaseous flow to the measurement cavity; an introducing device configured to introduce a laser incident optical signal having a variable wavelength into the measurement cavity; a generating device configured to generate a plurality of reflections of the laser incident optical signal in at least two separate points on each of said at least two mirrors during travel of the laser incident optical signal in the cavity; a measuring device configured to measure a transmitted optical signal resulting from an interaction between the laser incident optical signal and each isotope of the two isotopes in the measurement cavity; a calculating device configured to calculate the relative contents on the basis of the transmitted optical signal; and an optical measurement unit comprising said optical measurement cell, said optical measurement unit being directly connected to the outlet of said column, such that the gaseous flow directly enters the optical measurement unit free from chemical modification of the gaseous flow.