Spectroscopic monitoring of gas in liquid

Abstract

A spectrometer 100 for analysis of a gas within a liquid, comprising one or more optical sources 120, 110 configured to generate first probe light 121 at first wavelengths and second probe light 111 at second wavelengths, the first wavelengths including a wavelength of an absorption feature of the gas, and the second wavelengths offset from this feature, a controller 180 arranged to sequentially trigger the first and second lights, a sample interface 140 for interfacing the probe lights with the liquid, sample beam path optics 145 arranged to guide the probe lights through the interface to a photodetector 160, reference beam path optics 155 arranged to guide the probe lights along a reference path to a second photodetector 170 without passing through the interface, and an analyser 190 arranged to determine the gas species or generate an absorption spectrum based on the received signals. [Figure 1]