DID YOU KNOW?
When using any infrared technology for gas measurement other gases with a similar wavelength can show an increased CH4 value. For CH4, this can be seen in the presence of VOCs (volatile organic compounds). These gases are long chain hydrocarbons, which like methane are made up of a combination of carbon and hydrogen atoms. This has a positive cross gas effect, meaning that any influence from VOCs will be in addition to the CH4 composition of the gas mixture.
If VOCs are known to be present, or higher than expected values of CH4 are recorded, the use of an H2S / VOC filter for a second measurement will remove the majority of hydrocarbons other than Methane, providing more accurate results.