From automotive to aerospace, energy to environment and pharmaceuticals to petrochemistry, the requirement to analyse gases and molecules is ubiquitous.

Almost everything we use or consume will have been analysed in a laboratory at some juncture – and the rigours of gas analysis and control continue to escalate as the quest for purity intensifies and compliance grows ever-tighter.

Within the gases industry itself, gas control equipment can be found throughout air separation plants, on-board trucks and trailers, at cylinder filling sites, in the laboratory, and more.

In gasworld Global’s upcoming 6th issue of 2019, we take a closer look at gas analysis technologies, focusing on cavity ring-down spectroscopy (CRDS), off-axis integrated cavity output spectroscopy (OA-ICOS), paramagnetic and zirconia.


Now a member of automation firm the ABB group, Los Gatos Research (LGR) founder Anthony O’Keefe first used cavity enhanced absorption as an ultra-sensitive detection method in 1988 in the form of CRDS.

Since then, scientists at LGR have developed, and patented, OA-ICOS, a fourth-generation cavity enhanced laser absorption technology.



It directly measures absorption rather than only a cavity decay time with an optical path length of several kilometres.

“Therefore, it offers a linear response over a significantly wider dynamic range (many orders of magnitude and up to 100% mole fraction for some gases),” explains Steve Gibbons, Head of Product Management, Continuous Gas Analysers, at ABB Measurement & Analytics at ABB Process Automation.

“Compared to the first instruments that were developed in the 1990’s, this approach delivers superior performance and is orders-of-magnitude less sensitive to internal alignment of components and to variations in local temperature and pressure.”

“As a result, a modern OA-ICOS analyser is extremely robust and therefore ideal for use in a wide range of the most demanding applications and in remote locations.”

These high-performance analysers provide laboratory quality measurements anywhere and are increasingly used in hazardous industrial processes to measure trace contaminants in fuel gases, on-board vehicles and drones for detecting and mapping natural gas leaks, and on every continent measuring greenhouse gases in the air, water and soil.


The state-of-the-art technology represents the latest version of tunable diode laser spectroscopy and cavity enhanced spectroscopy techniques. But how will this technology evolve in the future and will digitisation have an effect?

LGR-ICOS 950 series

Source: ABB

“This inherently digital technology offers new opportunities for accurate measurements of trace gases and isotope ratios over several orders of magnitude dynamic range, continuously, and in real time without consumables, frequent calibrations or maintenance,” Gibbons highlights.

“Moreover, analysers based on OA-ICOS can now connect to cloud-based platforms allowing customers to rapidly record and analyse data, and rapidly share new information to enable improved understanding of complex environmental systems; control and optimise critical industrial processes; detect, map and quantify natural gas leaks; and improve other important applications requiring fast, reliable gas measurements in the field.”

“Whilst this represents a break-though, this is still an emerging technology when compared to, for example, paramagnetic oxygen analysers. So, who is to say how it might continue to evolve in the next two decades?”

gasworld will publish the full feature, titled ‘In focus… Gas analysis technologies’, in its upcoming Global 6th issue of 2019 edition, available by the end of May.