X-ray fluorescence (XRF) is a rapid chemical or elemental analysis method. High energy X-rays or gamma rays are used to excite the sample, resulting in the emission of characteristic secondary or fluorescent X-rays from the sample. Then these resulted X-rays will be detected by the detectors and converted into the corresponding signals, telling the qualitative and quantitative information of the sample. It is particularly used in the analysis of metals, ceramics, glass and for the research in geochemistry, forensic science and archaeology. A gas mixture of 90% argon & 10% methane (called as “P 10”) is used in the detectors.