Methane is known as a good absorber of infrared light. This is the reason why infrared detectors are used to detect its presence. Most infrared instruments are calibrated in percentage form. However, a few are calibrated in terms of parts per million - ppm. A basic infrared CH4 analyzer detects methane together with other closely related hydrocarbons. It gives final results with these minor gases included. However, the minor gases occur in significantly small amounts hence can be neglected during analysis.
In some extreme cases, the concentration of methane is very low and this calls for instruments that are more sophisticated. The type of CH4 analyzer used in such cases has to detect methane separately form the other gases. A CH4-specific detector is most appropriate. Filtration systems are employed to filter off other gases and particles. A spectrometer may have to be incorporated in order to get better results. The laser type of instruments can be used whenever CH4 detection has to be conducted separately from other gases. Laser detectors are able to determine the concentrations of various gases according to their specific frequencies and wavelengths.
There are a couple of factors to consider when purchasing a CH4 analyzer. First, the user must be conversant with operation of the instrument. Beginners may have to buy easy to use analyzers. The portability of the instrument is also an important consideration. Some analyzers are portable while others are meant to be fixed at strategic positions for CH4 detection. The portable types use DC power and can be powered by AA sized batteries. Laser analyzers are much better than traditional types when maintenance costs are concerned. Versatility of the equipment also matters a lot. Some instruments can only be used to monitor CH4 while others can monitor a wide range of gases.