Is Laser-OES Non-Destructive? Exploring the "Near-NDT" Nature of Laser-Based Analysis
In modern materials testing, maintaining product integrity while obtaining accurate, in-depth data is crucial. Laser-OES, or Laser Optical Emission Spectroscopy, has become a valuable tool in various industries for fast, accurate elemental analysis. But an essential question remains: Is Laser-OES non-destructive? In this article, we’ll explore how Laser-OES works, its impact on the materials it tests, and why it’s often referred to as a "near-nondestructive testing" (near-NDT) method.
Laser-OES is a type of spectroscopy that leverages a focused laser to vaporize a minuscule amount of material from the sample's surface. When the laser hits the sample, it creates a plasma containing ionized particles from the sample’s surface. The excited atoms in the plasma emit light at specific wavelengths, which are characteristic of the elements present in the material. By analyzing the emitted light, Laser-OES can provide a detailed breakdown of the sample’s elemental composition.
This technique offers several advantages:
However, like any other method involving vaporization, Laser-OES leaves a mark on the tested material, making the question of its destructiveness more complex. Specifically in the world of metals this topic has high relevance, whereas in minerals and other materials the effect is neglectable.
Many burnspots only become visible after same time, when they oxidize. In bright non-ferrous materials they remain widely invisible.
At QuantoLux products like the portable QLX1 or bench top QLX3, multiple pulses are used to hit the same spot, creating a similar appearance as the known burnspots from spark-OES, just way smaller.
Strictly speaking, Laser-OES cannot be classified as a completely non-destructive testing (NDT) method, because it requires some material removal to generate the plasma for analysis. However, the micro-burnspot left behind is often so tiny and shallow that it has minimal impact on the material's structural properties, mechanical strength, or overall usability.
For most practical purposes, the term "near-NDT" is more appropriate. Here’s why:
In many industries, this "near-NDT" nature of Laser-OES is adequate to ensure that the materials being tested meet regulatory and operational standards without significantly altering the material itself.
The near-NDT characteristics of Laser-OES make it highly valuable in fields where both precision and minimal invasiveness are required. Common applications include:
The near-NDT nature of Laser-OES offers a unique blend of benefits that make it highly suitable for many quality control and verification tasks:
Laser-OES represents a unique approach to material analysis, bridging the gap between destructive and non-destructive testing. While it does leave a tiny burnspot, the impact on the material is so minimal that it rarely compromises the material’s integrity, appearance, or function. Consequently, Laser-OES is commonly regarded as a "near-NDT" technique—offering the precision and detail of more invasive testing methods without the associated material damage.
This near-NDT classification makes Laser-OES invaluable in various industries where accuracy, speed, and minimal invasiveness are paramount. From alloy composition verification to quality control, Laser-OES allows manufacturers and engineers to test without disrupting. For most practical applications, the micro-burnspot’s size and shallow penetration render this technique as close to non-destructive as possible, making it an excellent choice for sensitive and precision-based testing environments.