Laser Diode Combats Cross-gas Interference

Gas detection

Laser Diode Combats Cross-gas Interference

29 Jan, 2014

Published over 12 years ago. See the latest and most current information on Gas detection.

Knowing exactly where methane (CH4) emissions are occurring on site is essential in order for AD biogas plants to comply with environmental enforcement agencies and save valuable energy, yet cross-gas interference can often cause a problem in identifying accurate emission locations and the gases present.

Flame Ionisation Detectors (FIDs) traditionally use hydrogen cylinders which can often require refills, and regularly costly servicing. They can also prove ineffective in adverse weather conditions and are unsafe to use in potentially explosive environments due to the flame. FIDs can also suffer from cross-gas interference, unlike the TDL-500 laser diode methane detector, from Geotech (UK). 

The  TDL-500 uses laser diode technology to accurately detect methane to 1ppm, with no interference from other gases. It also has optional  GPS functionality with an accuracy of 0.5 meters, compared to 10 metres with FID units, meaning it shows precisely where methane emissions are happening on site. It combines accurate sensitivity with speedy results, having a response time of 2 seconds.

Geotech's customers greatly benefit from this increased level of accuracy, Dwight El Mahassni, from Thermo Fisher Australia, stated "The instrument works extremely well. Its ability to distinguish from other volatile compounds in the atmosphere is very useful and the readings are very stable".

The TDL-500 is also ATEX certified, making it intrinsically safe and a more robust instrument out in the field.

Combining laser technology with a practical build, the TDL-500 is the ultimate in safe, time saving, and cost-effective methane emissions monitoring.

IET 36.2 Mar/Apr 2026

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