Spectro analysis usually means optical emission spectrometry (OES). A spark between an electrode and a flat, machined sample excites the metal, and the light emitted is split into wavelengths that identify and quantify each element. In aluminium plants and foundries it gives the full chemical composition in a few minutes. Handheld XRF and LIBS guns are also used for quick scrap sorting, but they are less precise for light elements such as magnesium and silicon.
Why it matters when buying
- A spectro report is the basic proof that alloy ingots, billets or scrap match the agreed grade.
- Ask for the heat or lot number on the report so it can be traced to the material dispatched.
- The sample must represent the lot: a single piece of scrap or one ingot may not reflect a mixed truckload.
- Spectrometers need calibration with certified reference standards; for disputes, agree a third-party laboratory in advance.
Notes
For scrap, spectro checks are often combined with a trial melt to measure recovery. The AluminumBazaar desk can arrange samples and spectro checks before dispatch. See also mill test certificate and the guide on checking scrap recovery.