主要论述了金属材料膨胀尺寸的测量。测量方法采用了差动式电容型膨胀尺寸传感器, 用 此传感器研制成的膨胀尺寸测试仪具有线路简单、成本低的特点, 输入输出是线性特性; 且具有较高的抗共模干扰能力(如温度影响)。同时给出提高测量精度和灵敏度的措施。 关键词: 金属材料; 膨胀尺寸; 传感器; 测试 Abstract: Them easu ring in st rum en t, w h ich in t roduces a differen t ial capacitance sen so r, can sim2 p lify circu it and low er co st. The relat ion betw een inpu t and ou tpu t is linear. It has a h igh ab ility to resist the common mode in terface such as temperatu re inf luence. The m easu res of imp roving the test p recision and sen sit ivity are also given. Key words: m etalm aterial; dilat ion dim en sion; sen so r;m easu ring