Use for the determination of total non-methane hydrocarbons in air (NMHC) as methane.
Samples are collected by precleaned and evacuated SUMMA canister or in a Tedlar bag using a pump. Composite samples may be collected using time-integrated sampling. Sample volume ranges from 1 to 20 liters. Ambient sampling will not be affected by humidity or rain.
The sample is analyzed by GC/FID with a cryogenic focus trap packed with glass beads. The sample is introduced into a cryogenic trap in which all hydrocarbons are trapped except methane. The trapped hydrocarbons are then thermally desorbed and introduced directly into the FID detector for quantification.
Canisters, Tedlar bags, GC/FID, Cryogenic trap, etc.
NMHC: 5.0 ppbv
A very low detection limit can be achieved because a large amount of sample can be passed through the cryogenic trap.
Only total non-methane hydrocarbon concentration can be reported.
TO-14 modified, ASTM 1945, TO-3 modified
Landfill well gas surveys, ambient air surveys, manufacture emission gas surveys, indoor air, stack gas analysis.