The Science
Dual-Wavelength UV Fluorescence:
Structural Defects + Biofilm
in One Pass
Aerodetex is built on the Videtex dual-wavelength platform — the same UV fluorescence science used in medical device inspection, now applied to aerospace fluid systems. 365 nm detects structural defects per ASTM E1417. 405 nm detects biofilm autofluorescence without dye. No competitor currently offers both in a single interchangeable probe.
Wavelength Science
Why Both Wavelengths Matter
365 nm — Long-Wave UV
ASTM E1417 Fluorescent Penetrant Inspection
Long-wave UV excites fluorescent penetrant dyes applied to metallic and composite surfaces. Under 365 nm illumination, dye that has penetrated surface cracks, porosity, or weld defects fluoresces brightly — revealing structural discontinuities invisible to white light. This is the established ASTM E1417 FPI protocol used throughout aerospace.
- Surface crack detection
- Porosity and weld defects
- Composite delamination
- ASTM E1417 / NASA PRC-6506 compliant
405 nm — Violet UV
Biofilm Autofluorescence — No Dye Required
Violet UV at 405 nm excites flavins (FAD, riboflavin) and NADH — metabolic compounds present in living and dead bacterial biofilm matrix. This is autofluorescence: the biofilm itself glows under 405 nm illumination without any applied dye. The same principle is used in medical device inspection (Endodetex) and is now applied to aerospace fluid systems.
- Biofilm matrix detection (no dye)
- Flavin (FAD/riboflavin) autofluorescence
- NADH metabolic marker detection
- Porphyrin detection (protein residue)
"If it is critical enough to inspect for structural defects in aerospace, it is critical enough to inspect for biofilm contamination in the same pass."
Comparison
Detection Capability by Wavelength
| Capability | White Light | 365 nm UV | 405 nm UV | Dual 365+405 nm ★ |
|---|---|---|---|---|
| Illumination wavelength | Broadband white (400–700 nm) | 365 nm long-wave UV | 405 nm violet UV | 365 nm + 405 nm |
| Structural defect detection | Gross only | ✓ ASTM E1417 FPI | Limited | ✓ ASTM E1417 FPI |
| Biofilm autofluorescence | ✗ None | Partial | ✓ Flavin / NADH | ✓ Full spectrum |
| Porphyrin detection | ✗ None | ✓ Strong | ✓ Strong | ✓ Strongest |
| Dye required for biofilm | N/A | Yes (FPI dye) | No (autofluorescence) | No (autofluorescence) |
| ASTM E1417 compliance | ✗ | ✓ | Partial | ✓ Full |
| Biofilm NDT capability | ✗ | Partial | ✓ | ✓ Industry first |
Hardware
Interchangeable Probes for Every
Aerospace Geometry
The Videtex platform's interchangeable probe system covers the full range of aerospace fluid system diameters — from ISS ECLSS plumbing to commercial aircraft galley lines.
3.9 mm
Lead aerospace probe — aircraft fuel tanks, hydraulic manifolds, potable water systems. Dual-view (front + side).
4.5 mm
Hydraulic system channels and military aircraft manifolds. Dual-view.
6.0 mm
Fuel tank inspection ports and large-bore systems. Dual-view.
1.8 mm
Narrow pass-through access and spacecraft ECLSS micro-plumbing. Single-view only (front OR side).
The Geometry Gap
Wavelength Is Only Half the Problem.
View Configuration Is the Other Half.
Even a 405 nm UV borescope with the correct wavelength will miss biofilm if it is configured for direct-view. A direct-view probe sees the lumen ahead — the open space in the center of the tube. Biofilm, pitting, staining, and moisture films all reside on the inner wall surface, which is perpendicular to the probe's optical axis. The Videtex side-view configuration rotates the optical axis 90°, placing the wall surface directly in the field of view as the probe advances.
Direct-View Borescope
All current aerospace competitors
- ✕Optical axis parallel to tube wall — wall is at grazing angle
- ✕Early-stage biofilm (days 1–7) is sub-millimeter and optically transparent
- ✕Even 405 nm UV cannot excite biofilm fluorescence at grazing incidence
- ✕Sees the lumen ahead; wall contamination is peripheral and out of focus
Side-View Borescope (Videtex)
First-in-class aerospace configuration
- Optical axis rotated 90° — wall surface is perpendicular to lens
- 405 nm UV illuminates wall at normal incidence — maximum fluorescence excitation
- Biofilm EPS matrix, fungal hyphae, and porphyrins fluoresce directly into the sensor
- Continuous wall scan as probe advances — no surface area missed
Common Objection: "We Already Have a 365 nm UV Borescope"
The Vividia UV-K-6010 and VSNDT VS-UVK60 are the most widely deployed UV borescopes in aerospace NDT. Both emit 365 nm UV and are correctly specified for ASTM E1417 fluorescent penetrant inspection (FPI) of structural defects. They are not capable of biofilm detection for three independent reasons:
01
Wrong Wavelength
365 nm excites FPI dye and porphyrins but does not efficiently excite flavins (FAD, NADH) — the primary fluorophores in living biofilm. 405 nm is required for autofluorescence of the biofilm EPS matrix.
02
Wrong View Configuration
Both Vividia and VSNDT probes are direct-view only. Even if wavelength were corrected, the direct-view geometry cannot illuminate the tube wall at normal incidence. Biofilm on the wall remains invisible.
03
Wrong Diameter
Both probes are 6.0–8.0 mm in diameter. Aircraft hydraulic lines, potable water distribution lines, and spacecraft ECLSS plumbing require 2.0–4.5 mm access. The Vividia and VSNDT probes cannot physically enter these systems.
Ready to Add Biofilm Detection
to Your Inspection Protocol?
Schedule a demonstration and see what dual-wavelength UV fluorescence reveals in your specific aerospace fluid system geometry.