Spark optical emission spectrometry is the workhorse for solid metal. An argon-shielded electric discharge vaporises and excites atoms at the sample surface, the emitted light is dispersed by a spectrometer, and intensities are converted to concentrations using calibrations built from certified reference materials of similar composition. X-ray fluorescence offers the same idea without the need for a conductive, flat surface: a beam excites inner-shell electrons, and the characteristic fluorescence identifies and quantifies elements, which makes handheld units useful for alloy sorting. Carbon, sulfur, oxygen, nitrogen and hydrogen are not accessible to optical emission at low levels and are determined by combustion or inert gas fusion: the sample melts in a crucible under a stream of oxygen or inert gas, gases are released and measured by infrared cells or thermal conductivity. Inductively coupled plasma optical emission spectrometry is used after acid dissolution for trace elements and for certification work. All these techniques depend on calibration, matrix matching and clean, representative samples.
- Spark Optical Emission Spectrometer for Metal Analysis — A spark optical emission spectrometer excites a machined metal surface with an argon-shielded discharge and measures the emitted light to determine many elements at once.
- Combustion Carbon-Sulfur Analyzer for Metals — A combustion carbon-sulfur analyzer burns a weighed metal sample with an accelerator in an oxygen stream and measures the carbon dioxide and sulfur dioxide released with infrared cells.
- Inert Gas Fusion Oxygen-Nitrogen-Hydrogen Analyzer — An inert gas fusion analyzer melts metal samples in a graphite crucible under inert gas and measures the released oxygen, nitrogen and hydrogen.
- Handheld XRF Alloy Analyzer — A handheld XRF alloy analyzer identifies alloy grades by measuring X-ray fluorescence from a test surface, making positive material identification possible in the warehouse or on installed equipment.
- Inductively Coupled Plasma Optical Emission Spectrometer for Metal Assay — An inductively coupled plasma optical emission spectrometer measures trace and major elements in dissolved metal samples, separating the metal in acid first.
How do I choose the right variant?
Decide from the elements, the levels and the sample form. For production control of solid metal, spark optical emission gives fast multi-element results from a machined surface and is the usual choice, with the spectrometer configuration matched to the base metals and element ranges you analyse. Combustion and inert gas fusion instruments are required when carbon, sulfur, oxygen, nitrogen or hydrogen form part of the specification, and they need their own sample preparation and reference materials. Handheld X-ray fluorescence suits incoming inspection, alloy sorting and positive material identification on installed parts, but cannot measure carbon or low atomic number elements and needs careful radiation management. Inductively coupled plasma is preferred for trace and tramp elements, for non-routine matrices and for validating other methods. Check detection limits, the number of elements and channels, calibration standards available, argon or gas supply and service support before committing.
Metal Analysis are specified in steel and alloy grade verification, foundry melt control and charge optimisation, positive material identification of installed parts, gas content control for steel cleanliness and certification of reference materials.
Which standards and certifications apply?
Work with Metal Analysis is commonly governed by ASTM E415, ASTM E1086, ASTM E1019, ASTM E1479, ISO 14284, ASTM E1806 and IEC 61010-1. Instrument certifications such as CE marking are confirmed per configuration and never assumed.
What are the key considerations before purchase?
Everything depends on calibration and reference materials, so keep a set of certified standards covering each element range and renew them before they expire. Condition the sample surface correctly: machined for spark emission, flat and clean for X-ray fluorescence, uncontaminated chips for combustion. Reference the instrument daily with a control sample and confirm drift before releasing results. Maintain gas supplies at the specified purity, since moisture and oxygen in argon degrade spark stability, and check crucibles, electrodes, filters and reagents on a schedule. Control contamination between samples: clean the spark stand, change crucibles and use new tools. Radiation and laser safety programs, fume extraction for acid digestion and safe handling of compressed gases are part of normal operation, and records of calibration, verification and maintenance should travel with the results.
