Some electrolyte compounds react with multiple gases. This is what we term a ‘cross gas effect’, the effect of this is results in a false mA output of the cell for the gas measured.  Electrochemical CO cells industry-wide, can be affected by other gases, some typical gases which can influence your CO reading are; H2 and H2S however others do exist.

For removal of H2S from the gas mixture we supply an H2S / VOC filter which uses activated carbon to remove all H2S within the mixture.  We also offer a unique H2 compensated (up to 1%) version of our CO sensor, to help when monitoring CO in the presence of H2.  If H2 is above 1% this could permanently damage the cell. For full information on best practise monitoring in the presence of H2 please contact Geotech.

LFG pumping trials with Automatic Flare Systems (AFS)

Application Landfill gas Customer Automatic Flare Systems (AFS) Requirement Managing director at AFS, Steve Willacy said, “We want continuous landfill gas monitoring and analysis and to use a data logger to record the results from the gas analyser.” Operation AFS uses its mobile flare skid for landfill gas pumping trials to analyse the quantity and…
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Biogen Greenfinch Westwood

Beyond keeping the engines running, Westwood’s CHPs have an impressive 99 percent uptime at 41 percent biogas to electricity and useable-heat efficiency. These high rates will make substantially positive profit impact over the several years of investment payback.  Watching the biogas as it comes from the gasholder and travels towards the CHPs and water heating…
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An analyser is only as accurate at the moment of calibration.  Following this point, electrochemical cells / sensors will begin to degrade and this can be increased through heavy use.  However alongside ensuring regular servicing, we recommend you perform regular user calibrations and checks.  By using span gases similar in composition to your typical CO values, the accuracy of the CO channel can not only be maintained, but can be improved for your specific application. Always ensure that your analyser is purged with fresh air between readings and at the end of the day’s readings to ensure no residual gas remains in the analyser.

Other Gases


Methane is 20 times more of a potent greenhouse gas than CO2. The anaerobic process has been replicated artificially in the form of anaerobic digesters to produce cleaner energy to power houses and even cars. Through monitoring with a Geotech analyser you can optimise your process to ensure you make the most from your plant as well ensuring that your engines aren’t damaged if CH4 drops below optimal levels.

Carbon Dioxide

Carbon dioxide is critical to maintain at a constant level during IVF and cell culture growths. It’s also a bi-product of respiration and in confined spaces these levels can increase. Careful analysis of CO2 within an IVF chamber using a Geotech analyser can ensure that embryos develop correctly. The detection of CO2 in confined spaces e.g. a lorry can be indicative of a stowaway.


Oxygen is required in the combustion process where CH4 is burnt to produce heat and energy but too much can cause damage to the engine. Pinking occurs when too much oxygen is present in the engine during combustion. Continuous analysis with a Geotech analyser allows you to set alarms when thresholds of O2 are passed which in turn can close down the engine saving expensive damage and increased downtime.

Carbon Monoxide

Carbon Monoxide is produced during incomplete combustion, this occurs when there is limited levels of oxygen and increased Carbon Dioxide. Levels of 90ppm or greater can be indicative of underground fires on a landfill site. Geotech offers unique technology to gain accurate results about the health of your landfill site and to ensure the safety as well as value of the cell is retained.

Hydrogen Sulphide

Hydrogen sulphide is particularly harmful when biogas is used in internal combustion engines. Its chemical reactions and those of its combustion product - sulphur dioxide - lead to corrosion and wear on engines. Through careful monitoring of this using a Geotech analyser you can ensure the health of your engine and save costs through engine downtime or increased servicing.


Electrochemical sensors are used industry wide, they are micro fuel cells designed to provide an accurate, stable and low cost measurement technique that can be easily maintained in a portable analyser.


Ammonia is one of the digestion products in anaerobic digestion. If nitrogen-rich feedstocks are used, inhibition by ammonia is often the reason for a process imbalance. Therefore, monitoring NH3 concentrations in the digester helps to estimate if ammonia inhibition is causing the process imbalance.

Nitrous Oxide

Nitrous oxide is widely used in hospitals as a general anesthetic. It’s important that concentrations are accurately measured and also leaks and exposure levels are monitored closely, as long term and repeated exposure can be harmful to human health.