Standard Ruler (disambiguation)

Standard Ruler may refer to:

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  Standard ruler (geometry)

  A ruler-like reference measure used in geometric constructions to define lengths or calibrate scale.

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  Standard ruler (optics/engineering)

  A precision length reference used in optical/engineering metrology to calibrate measurement instruments.

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  Ruler (standard) in photography/geometric calibration

  A known-length reference target (a “standard ruler”) used to convert pixels to real-world distances in imaging.