Ａ型读片测量尺是笔者在工作实践中设计而成的 ,使用简便 ,测量准确。现介绍如下。1　制作目的　方便测量图像大小2　制作材料　塑料板。3　制作方法　如图 13 .1　裁制两块规格相同的塑料板 ,ＡＢ板、ＡＢ′板。板长 2 0ｃｍ ,宽 2 .0ｃｍ ,厚 0 .2ｃｍ。3 .2　在两板Ａ端内侧 A-type reading film measuring ruler is designed by the author in the work of practice, easy to use, accurate measurement. Now introduced as follows. 1 production purpose to facilitate the measurement of image size 2 production of plastic materials. 3 production methods shown in Figure 13.1 cut the same two specifications of the plastic board, AB board, AB ’board. Plate length 20cm, width 2 .0cm, thickness 0 .2cm. 3 .2 Inside the A plate of both plates