Glossary

Term	Meaning
3D defect	The tool that estimates concrete missing from a face, against a reference fitted to the sound concrete around it. See Measure missing concrete
Affected area	The damaged part inside a 3D defect outline — always smaller than the outline you drew
AI proposal	A defect proposed by an automatic detector: a place, a type and an outline. Not a finding until a person signs it off. See About AI proposals
Base surface	The level a volume is measured against, chosen by you. See Volume base surfaces
Category	The type of defect: crack, spalling, seepage, corrosion, erosion, deformation, vegetation or other
Cut and fill	Material above the base surface (cut) and space below it with no material in it (fill)
Depth profile	A cross-section of the surface between two points, measured square to the straight line between them. See Measure a depth profile
Dismiss	Record that an AI proposal was reviewed and rejected, with a reason from a fixed list
Draft	A finding that nobody has signed off. In the records, but not in reports
Explain	The toolbar mode in which clicking anything tells you what it means, without pressing it. See Ask AerTwin what something means
Finding	A record tied to a place on the structure: a point observation, a saved measurement or a decided AI proposal
Fly to	Return the view to where a finding was recorded
Group	A named part of the structure — “Pier 3, west face” — under which findings are filed. Numbered GRP-001 and so on. See Group findings by part of the structure
Instrument mark	A mark showing where a monitoring instrument is installed, with its tag and type. It carries no reading
Missing concrete	The volume of concrete gone from a face, measured by the 3D defect tool. Always shown with a quality word
Model	The 3D model of the structure, built from the capture photographs. Also called the twin
Navigate	The state in which the mouse moves the view rather than placing points
OBS number	A finding’s number — OBS-001 and so on. Issued once and never reused
Outline check	A mark that an outline’s points landed on the wrong surface (outline), or that there are too few points to tell (unchecked)
Plan	Seen from directly above, as on a map: Area (plan), Length (plan)
Point history	The earlier positions of a saved outline’s points, with what each measured. See Change the shape of an outline
Quality word	Good, Fair, Indicative or Not measurable: how far to trust a missing-concrete figure. See Quality words
Reference	For a 3D defect: where the sound face used to run, fitted by the tool. You do not choose it
Review	Working through AI proposals one at a time to sign off, dismiss or skip each one
Saved view	The view stored with a finding. Fly to returns to it, and its PDF page is rendered from it
Second review	An optional, independent sign-off by a second engineer with the Admin role. Shown as ✓✓
Section plane	A plane that hides part of the model so that you can look inside it. Changes only what is drawn
Session	The time a cloud computer is reserved for you while you work on a structure
Severity	How urgently a finding needs attention: critical, high, medium, low or info. Always chosen by a person
Sign-off	A named engineer’s acceptance of one version of a finding. Shown as ✓. See Sign off a finding
Source photograph	A calibrated capture photograph that shows a point on the structure. See View the source photographs of a point
Status	Where a finding is in its life: open, monitoring, resolved or closed. Changing it does not affect the sign-off
Team activity	The list of what members of your projects have saved recently. See See what your team has done
Version	Every change to what a finding asserts creates a new version. A sign-off applies to one version