摘要 |
A method and apparatus for determining the safety of a gas mixture containing flammable components such as methane together with ethane or other hydrocarbon, together with a diluent gas. The method includes the filtered infrared spectroscopy of the gas mixture in a gas cell using a filter. The peak transmission wavelength and bandwidth of the filter are so chosen to provide an output, when an infrared light source having a flat wavelength distribution is used, indicative of the % LEL of the gas mixture, within a predetermined tolerance. The filter may be a gas correlation filter containing a mixture of methane and ethane, together with a diluent gas. |