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What a measurement rests on.

Where the scale comes from, what the measure tool does with it, and when it refuses.

Measurement & scale

Every quantity measured off a drawing rests on one number: how much real length a point on the sheet stands for. Blueprint Auditor reads that from the drawing where the drawing states it, and says so rather than assuming one.

Where the scale comes from

  • The title block. A sheet that prints "1:50" or "1/4″ = 1′-0″" is read, and the measure tool starts from that with the scale shown beside it.
  • Your own calibration. Type a scale and it governs from then on, which is the answer for a sheet plotted to fit the paper.
  • Nothing. A sheet that states no scale is left uncalibrated, and shapes drawn on it are kept as shapes with no quantity until a scale is set. They are counted in the export as excluded, and never quietly at 1:100.

A CAD file is different: DWG and DXF carry real units, so a length is read from the file rather than from a printed statement.

What the measure tool produces

  • Lengths, areas and counts, each against a named condition with your own cost code on it.
  • An area becomes a volume when you give it a depth, and a length becomes an area when you give it a height. The depth is typed, never inferred from a hatch pattern.
  • A deduction is subtracted from its condition and kept visible: the export carries the gross, what was taken off, and how many deductions there were.
  • A shape drawn but not inked is a proposal, not a measurement. It is excluded from every total, and the row says why.

Getting it out

CSV for a sheet you already have, or a workbook where each condition's total is a SUMIF formula over the quantity column — so a row corrected in Excel moves its total, and deductions sum correctly because they are written negative. A second sheet in the workbook records the scale the quantities were measured at and every shape left out of a total.

What it will not do

  • It will not measure a sheet with no scale. A wrong scale turns every quantity on the drawing into a wrong quantity, which is worse than no quantity.
  • It will not convert a nominal figure into an effective one. What is measured is what is drawn.
  • A scanned sheet can be measured once you calibrate it, but nothing on it is read automatically: there is no text and no geometry to read.