DSS-A.01.03 — Desiccant Dust / Fines in IGU Cavity

Particulate fines (typically white/gray) released from or tracked by the spacer/desiccant system within an insulating glass unit (IGU) cavity. Presents on cavity faces (#2 and/or #3) and is not accessible in-place. IGU surface numbering and “between-pane” determination follow the VIS conventions.

• Discrete specks or light “peppering” scattered near the spacer or in streaks/bands within the cavity; may increase over time as the unit ages.
• Most apparent in raking light or against dark interiors; does not respond to exterior/interior cleaning.
• Apparent location is stable under parallax (i.e., the specks move with the glass/its reflection consistently as a between-pane feature, not on the outer face).

• Location cue (parallax): Fixed parallax confirming #2/#3 cavity faces → record as a between-pane condition.
• MSRT (surface-catch): Not applicable to the cavity faces; do not attempt tactile checks on inboard/outboard faces to infer between-pane relief. (MSRT supports field classification only on exposed faces under VIS; use visual + location cues for cavity features.)
• Surface numbering on forms: Log #1-#4 per VIS and note “cavity (#2/#3)” in remarks.

Evaluate at 12 / 36 / 72 in with normal incidence + oblique sweep (~60°-120°) under raking light; surfaces must be clean/dry (Non-Invasive Reveal) to exclude face-side residues.

• CAT-5 (Non-repairable / out of in-place scope by location). Between-pane/cavity contaminants are not addressable in place; document and refer per project protocol (manufacturer/warranty/replacement).

Not applicable as a surface-relief quantity on the exposed faces. The feature resides on #2/#3 cavity faces or within the spacer/cavity environment; field acceptance remains appearance-only and location-based under VIS.

• vs. Exterior/interior dust or paint specks (R-family): Face-side residues change with Non-Invasive Reveal; true cavity fines do not. Use parallax to confirm between-pane location.
• vs. Spacer smear/bleed (A.01.04): Smear appears as continuous bands/films along the spacer sightline rather than discrete specks; both are CAT-5 by location. (Document with close oblique photos and refer.)
• vs. Low-E coating rub/patchiness on worked surface (Co-family): Coating anomalies are on an exposed worked face and are disallowed at acceptance; cavity fines sit behind the face (CAT-5). Log surface numbering to avoid mis-ID.

• Photo set (VIS): 12 / 36 / 72 in, normal + oblique; include raking frames and at least one sequence demonstrating fixed parallax relative to the reflection.
• Forms: Pane ID; product family; surface numbering (#1-#4; laminate-internal); “cavity (#2/#3)” noted; lighting/time; geometry checklist.
• Narrative note: “Between-pane particulate; non-responsive to Non-Invasive Reveal; CAT-5 by location.” (VIS separates classification from acceptance; factory/warranty governs IGU integrity.)

A.01.03 Desiccant Dust/Fines (IGU Cavity) - Discrete particulate visible on #2/#3 faces confirmed by fixed parallax under VIS geometry. Non-responsive to Non-Invasive Reveal; MSRT not applicable to cavity faces. CAT-5 (between-pane; out of in-place scope). Documented with photo set and surface numbering; refer to manufacturer/warranty per project protocol.