What is the primary purpose of calibration gases in landfill gas monitoring?

The primary purpose of calibration gases in landfill gas monitoring is to ensure the accuracy and reliability of the gas analyzers used to measure the concentration of different components in landfill gas, such as methane, carbon dioxide, oxygen, and hydrogen sulfide. Calibration gases are gas mixtures with precisely known concentrations of the target gases. By exposing the gas analyzer to these known concentrations, the instrument's response can be adjusted to match the known values, correcting for any drift or inaccuracies in the sensor readings. Regular calibration is essential to maintain the accuracy of the gas analyzer over time, as sensor performance can be affected by factors such as temperature, humidity, and exposure to contaminants. Accurate gas monitoring data is critical for assessing landfill gas generation rates, optimizing gas collection system performance, ensuring compliance with regulatory requirements, and detecting potential safety hazards. Calibration gases are typically certified reference materials traceable to national or international standards to ensure their accuracy and reliability. The calibration process typically involves a zero calibration (using a gas with zero concentration of the target gas) and a span calibration (using a gas with a known concentration close to the expected range of measurement).