14.2 Paired Image Documentation and Presentation

Numbers in a table convince engineers; images convince the people who open the panel. Level II presentation standards require paired documentation: a radiometric thermal image and a visible-light visual of the same target, prepared so a third party can locate the fault, trust the measurement markups, and avoid being misled by cosmetic processing. This section covers pairing rules, FOV guidance, scale/palette consistency, annotation discipline, and honesty in image processing.

Why Pair Thermal with Visual

Infrared alone is often a grayscale or false-color blob among look-alike metal boxes. The visual image supplies:

Rule of practice: If you cannot identify the asset from the visual alone, the pair is not ready for a quantitative finding release.

Same Field of View (FOV) Guidance

“Paired” means corresponding, not merely “both exist somewhere in the report.”

Practical FOV workflow

1. Compose the IR for radiometry (focus, fill factor / spot size, angle).
2. Capture visual from the same position immediately after (or use camera fusion if the FOV match is honest).
3. If the visual must zoom for a nameplate, add a second visual: context wide shot + detail tag shot—and still keep a visual that matches the IR FOV for the fault location.
4. In the report, place pairs side-by-side or stacked with a single caption linking to the finding ID.

Fusion overlays are acceptable when alignment is accurate. Misregistered fusion that paints heat on the wrong breaker is worse than separate clean pairs.

Scale, Span, and Palette Consistency

Readers compare images. If every IR uses a random auto-span, a healthy motor can look “on fire” next to a true fault that was manually compressed.

Clipping honesty: If the hotspot exceeds the displayed max, the scale bar or caption must say so—or expand span. Silent clipping understates severity visually even when the spot meter is correct.

Annotations That Match the Data

Annotations are part of the measurement record, not decoration.

Annotation integrity checks

1. Spot location in IR matches the component described in the visual and table.
2. Reported temperature equals the on-image readout (no manual typo).
3. Reference spot for ΔT is on a true peer under similar load—not ambient air unless ambient-referenced method is declared.
4. Annotations survive export (not only on the camera screen).
5. Visual annotations (if any) do not imply a thermal measurement that was not taken.

Image Processing Honesty

Post-processing is allowed for clarity, not for advocacy.

Palette ethics exam point: There is no single “correct” palette, but inconsistent or extreme choices that change the story without changing the data are report defects. Level II prefers: (1) radiometric truth in numbers, (2) fair visual encoding of that truth, (3) captions that explain any special display choice.

Processing checklist before PDF freeze

1. Scale bar present; units consistent with table.
2. Palette consistent across comparison set.
3. No auto-span surprises between sister phases unless noted.
4. Pair FOV match verified.
5. Annotations match finding IDs and ΔT math.
6. Reflection or solar artifacts labeled when present so readers do not treat them as faults.
7. File names or embedded metadata retain link to raw radiometric files for audit.

Report Layout Patterns

Captions should be self-contained: equipment ID, date/time, key parameters or “see table,” measured T / ΔT / Priority, and one-line recommendation pointer.

Worked Presentation Scenarios

Scenario A — FOV mismatch. IR shows a hot lug; visual is a doorway photo of the MCC room. Level II rejects the pair, requires a visual of the same cubicle face with legible ID.

Scenario B — Palette drama. Single P3 finding exported in ultra-contrasting rainbow with a 5 °C span while peers use 50 °C span. Client panics. Level II re-exports comparison set on common span, keeps Priority 3 math unchanged, and explains display correction.

Scenario C — Annotation error. Spot sits on a shiny bolt reflection; table claims joint temperature. Level II moves measurement to taped surface or correct material, reclassifies if needed, and re-annotates.

Scenario D — Honest clipping fix. Hotspot reads 120 °C; display max was 80 °C so the image is a white blob. Level II expands span, keeps spot value, and shows sister phase on the same new span for fairness.

Common Traps

Summary for Recall

Level II image documentation is paired, co-located, and fair. Thermal plus visual images share field of view so identity and defect location are obvious. Scales, spans, and palettes stay consistent enough for honest comparison; scale bars and units always appear on quantitative IR frames. Annotations must mark the real measurement and match the table. Processing may clarify but must not manufacture or hide severity—misleading palette or span games are ethics failures as much as technical ones. When in doubt, show the numbers clearly and make the pictures agree with those numbers.