The Science Behind NIR’s Non-Destructive Magic

Jul 01, 2025

Near-infrared (NIR) spectroscopy revolutionizes material analysis by extracting critical data without altering samples. Its secret lies in harnessing light-matter interactions at 950–1650 nm – where photons reveal molecular secrets through two key mechanisms:

 

1.The Physics of Non-Destructive Detection

 

Diffuse Reflection Mode

When NIR light hits solid/granular samples (e.g., grains), it:
▶ Penetrates 1–5 mm beneath the surface
▶ Scatters due to interactions with C-H/O-H bonds
▶ Reflects back carrying composition data

Example: Analyzing wheat protein without grinding kernels.

 

Transmission Mode

For liquids/transparent materials (e.g., oils):
▶ Light passes through the sample
▶ Specific wavelengths are absorbed by molecular bonds
▶ Detector measures attenuated light intensity

Example: Testing olive oil purity in seconds.

 

2.IAS-5100’s Light Path Genius: Patented Side-Illumination

 

Traditional NIR struggles with uneven samples. IAS-5100’s innovation solves this:

How it works:

Light Mixing Technology: Side-emitted light envelops particles, tripling effective analysis area.

No Grinding Needed: Whole grains/pellets yield lab-grade accuracy (SEC* ≤0.2%).

Real-world impact: Detects hidden moisture pockets in rice grains missed by top-down systems.

 

3.The Quantum Mechanics of Light-Matter Interaction

 

Molecular "Fingerprint" Decoding

Energy Absorption:
Photons excite molecular bonds (C-H, O-H) to higher vibrational states.
ΔE=hν(h=Planck’s constant, ν=light frequency)ΔE=hν(h=Planck’s constant, ν=light frequency)

Spectral Signatures:
Each bond absorbs unique wavelengths (e.g., O-H: 1450 nm, C-H: 1730 nm).

Signal Interpretation:
Detected absorption intensities convert to chemical concentrations via chemometric models.

 

Why Penetration Depth Matters

Sample Type

Optimal Depth

Data Accuracy

Whole grains

2–3 mm

Protein: ±0.25%

Powders

0.5–1 mm

Moisture: ±0.15%

Oils

Full transmission

FFA*: ±0.05%

*FFA: Free Fatty Acid

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    Our goal is to enhance the efficiency of trade and production, enable traceability, and promote the sustainable development of society through spectral analysis technology.

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