Technical directory · Maintenance
Before and after photographs
Photographs can show visible deposits removed but cannot prove combustion safety or unseen ducts were cleaned.
What to observe
Agree on representative access points and identifiable before/after views before work starts.
A field example
A tightly cropped dust photo is weak proof without the equipment label or recognizable access point. Agree in advance on views that show the component, not just a handful of material in a vacuum.
What the written work should say
Ask for a written scope and post-work operational check alongside pictures.
Where this task stops
Beware unrelated stock photos or close-ups that cannot be matched to your equipment.