一、前言众所周知,引伸计是测定金属材料微小变形的必要仪表之一,目前国内外已有多种类型、规格的引伸计生产并提供使用。但大多数引伸计具有装卡麻烦、功效低,辅助与准备时间较长,对被测试样的标距长度限制较严,或易于损坏等缺点。鉴于此,我所于82年研制成功 ZY—Ⅱ型凸轮引伸计如图1所示,经有关计量部门检查、标定、试验, I. Preface As we all know, extensometer is one of the necessary instruments for the determination of small deformation of metal materials, at home and abroad have a variety of types and specifications of the extensometer production and use. However, most extensometers have the disadvantages of jamming, low efficacy, longer auxiliary and preparation time, more limited gauge length of the tested sample, or easy damage. In view of this, I successfully developed in 82 ZY-Ⅱ cam extensometer shown in Figure 1, the relevant measurement department inspection, calibration, testing,