Stationary 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.

The optic disperses this light and detectors measure the intensity of each element's lines. Calibrated against certified alloy standards, the instrument reports concentrations across the whole matrix in seconds — from trace residuals to major alloying elements.

• 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

Stationary arc/spark OES

Floor-standing analysers such as the SPECTROMAXx, SPECTROLAB S and SPECTROCHECK apply this principle with the stability and precision a foundry or mill laboratory needs for routine grade control. Nucleus configures, installs and calibrates the stationary SPECTRO range across India.