本技巧将介绍弦笛深度的测量，定义为从笛谷最低点到与两个相邻笛尖相切的假想线的垂直距离。用于测量凹槽深度的深度计底座位于两个相邻的凹槽尖端上，形成这条线。

This TIP will address the measurement of chordal flute depth defined as the perpendicular distance from the lowest point of a flute valley to an imaginary line tangent to two adjacent flute tips. The base of the depth gage used to measure flute depth, which rests on the two adjacent flute tips, forms this line.