Air-Based LIBS: Built for Speed and Simplicity
Air-based LIBS systems operate directly in ambient conditions, making them quick to deploy and easy to use. For applications focused on rapid identification and high-throughput sorting, this approach is effective and widely used.
However, operating in open air introduces variables that cannot be controlled.
Oxygen and nitrogen in the atmosphere interact with the plasma, influencing signal quality and making certain measurements — particularly carbon — more complex and less consistent.
Best suited for:
- Rapid alloy identification
- Scrap sorting and verification
- High-throughput inspections
Argon-Purged LIBS: Engineered for Reliable Results
Argon-purged LIBS systems create a controlled environment around the plasma, significantly reducing the influence of atmospheric gases.
This isn’t a small improvement — it’s a fundamental shift in measurement conditions.
By stabilising the plasma and improving signal clarity, argon purge enables more consistent, repeatable, and dependable results, particularly when analysing elements that are difficult to measure in ambient air.
Why it matters:
- Minimises interference from oxygen and nitrogen
- Improves plasma stability and signal strength
- Enhances repeatability across measurements
- Supports more reliable carbon analysis in real-world conditions
The Real Difference: Convenience vs Confidence
Both approaches can deliver fast results.
But when the decision you’re making depends on the accuracy of that result, the gap becomes clear.
Comparison Table:
| Feature | Air-Based LIBS | Argon-Purged LIBS |
| Portability | High | High (uses small internal cartridges) |
| Detection Limit | Higher (less sensitive for trace elements), approx.300-800 ppm C | Lower (down to 20ppm C) |
| Speed | Fast (<1 second) | Fast (~1-2 seconds including purge) |
| Spectral Signal | Weaker; subject to atmospheric absorption | Enhanced by 2x to 10x due to plasma confinement |
| Atmospheric Noise | High interference from nitrogen and oxygen | Argon “shields” the plasma from air contaminants |
| Consumables | None | Requires argon |
| Common Use | Quick sorting, basic grade ID | Precise carbon and CE measurements. Can be used for quick sorting and basic grade ID. |
Where CALIBUS Stands Apart
The CALIBUS LIBS analyser range is designed for users who need more than just a quick answer — they need an answer they can trust.
By combining true portability with an argon-purged measurement environment, CALIBUS enables:
- Confident material verification
- Improved consistency across operators and conditions
- Reduced risk of misidentification or costly errors
This makes it particularly valuable in applications where carbon content and material integrity directly impact performance, safety, or compliance.
The Bottom Line
Air-based LIBS delivers speed and simplicity — and for basic identification tasks, that may be enough.
But when accuracy, repeatability, and confidence are critical, measurement conditions cannot be left to chance.
Argon-purged LIBS provides the controlled environment needed to deliver more reliable results — especially for challenging elements like carbon.
For professionals making real-world decisions on the shop floor, in the field, or in quality control, that difference isn’t marginal.
It’s essential.
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All technical information and data presented in this article are intended as a general guide only. Specifications, performance, and applications may vary depending on operating conditions.
ARUN Technology Ltd. accepts no responsibility for errors or omissions. Reproduction, distribution, or use of this material without prior written permission is strictly prohibited.
