Tunable Laser Spectroscopy

Dec. 21, 2018


LANDTEC SEM5000 methane (CH4) detector from QED is a laser-based device that is accurate down to 0.5 ppm. No flame is required, a huge benefit for sampling in a potentially explosive environment. No external gas bottle is required for operation; the laser technology also eliminates the risk of flame out, so the user does not lose time stopping and relighting. It comes with an integral GPS and Bluetooth that eliminates the need for a secondary device for data storage and GPS. The detector holds up to 480 hours of scan data – almost 3 months! – before it must be downloaded. It also features an ergonomically designed package that weighs only 3.5 pounds, less than half that of other SEM monitoring options.


The detector also features a “hot swap” removable and rechargeable battery, which means users charge the battery, not the instrument. When the charge from one battery has been depleted, users can simply swap to a fully charged battery and keep working. Each battery provides about 10 hours of operation on a single charge. Readings can be saved to your computer using the proprietary SEMsoft software package, which comes with multiple reporting functions and choices, easy upload for site maps and scan paths, and customizable indicator points based on the scan. The software formats the scan data into the standard .csv report, and auto-fills industry standard background reports.


Efforts to capture, control, and measure excess landfill gases are critically important, given current regulations around landfill emissions. Surface emission monitoring is required by the EPA, though not all technologies approved to perform SEM are equal. New laser-based technology, like the SEM5000, meets and exceeds EPA Method 21 requirements for quarterly SEM monitoring. The device’s versatility and convenience helps landfills to meet the EPA’s SEM requirements without experiencing some of the drawbacks of other technologies in terms of safety, efficiency, and ease of use.