This device monitors emissions at landfills
The Landtec SEM5000 methane detector (photo) is designed for surface-emissions monitoring (SEM) at landfills. The lightweight and ergonomically designed SEM5000 uses patented laser technology with a frequency that is tuned specifically to methane, so readings are not affected by cross-gassing, says the manufacturer. The SEM5000 meets or exceeds U.S. Environmental Protection Agency “Method 21 — Determination of Volatile Organic Compound Leaks” requirements for quarterly SEM monitoring, according to the company. Unlike flame-ionization devices (FIDs), the SEM5000 uses laser technology, so there is no cross-gas effect or false readings due to the presence of other gases or hydrocarbons, as with FIDs. No flame is required — a particular benefit for sampling in a potentially explosive environment, says the company. No external gas bottle is required for operation, and the technology is accurate down to 0.7 parts per million (ppm). — QED Environmental, a subsidiary of Graco Co., Dexter, Mich.