Arc/Spark OES: Working Principle

What is arc/spark OES?

Arc/spark optical emission spectroscopy is the reference technique for the direct analysis of solid metal samples. An electrical discharge between an electrode and the metal surface vaporises and excites a small amount of material, and the light it emits is measured to determine the alloy's full elemental composition — including light elements such as carbon, phosphorus, sulphur and nitrogen that matter for grade control.

It is the backbone of quality control in foundries, steel mills, die-casting and metal recycling, where fast and accurate composition results decide whether a melt or a batch is on grade.

How it works

A controlled arc or spark discharge is struck between a counter-electrode and the metal sample under an argon atmosphere. Each discharge ablates and excites atoms from the surface; as those atoms relax they emit light at wavelengths characteristic of every element present.

SPECTRO's portable and mobile analysers bring this laboratory technique to the material itself, so incoming goods, large castings and installed components can be verified on the spot without cutting samples.

• Direct analysis of solid metals with minimal preparation
• Measures light elements (C, P, S, N) that XRF cannot
• Fast, simultaneous multi-element results
• Excellent precision for grade verification and melt control
• Rugged enough for foundry and mill-floor environments

Portable and mobile arc/spark OES

The SPECTROTEST and SPECTROPORT analysers deliver arc/spark performance in transportable form for on-site alloy identification and verification. Nucleus supplies and supports the full mobile SPECTRO range across India.