GB/T 20975.21-2008 Determination of calcium content in aluminum and aluminum alloys by flame atomic absorption spectroscopy (AAS). The aluminum and aluminum alloy samples are first processed to convert the calcium element into a detectable solution state. Using a Flame atomization device to atomize calcium, a Light spectrum instrument measures the absorption degree of calcium atoms to specific wavelengths of light (Absorbance). Accurately calculate the calcium content by Absorbance according to the pre-defined calcium standard Linear dispersion. Sample Handling, instrument operation, measurement environment and data processing are detailed in the standard, providing a reliable method for mass testing of aluminum and aluminum alloy products, helping to control calcium content and ensure product performance.