Line gauge: Measuring ruler used for copyfitting and measuring type . Also called Type gauge.
量度字体大小和配稿用尺。亦称字尺。
英语百科
Ruler
A ruler, sometimes called a rule or line gauge, is an instrument used in geometry, technical drawing, printing, engineering and building to measure distances or to rule straight lines. The ruler is a straightedge which may also contain calibrated lines to measure distances.