试论杆式多点变位计测杆的位移传递精度

多点变位计按其原理可分两类：一类将位移传感器安设于钻孔内部，直接测量被测部分；另一类传感器置于孔口，间接测量被测部分．但后者的缺点是增加了位移传递误差．精度测试设备由尾座、约束墙、测头三部分组成，分5方面考察测杆位移传递精度：（1）迟滞（死区）非线性；（2）迟滞；（3）单向线性；（4）小位移特性；（5）重复误差．此外，摩擦、杆件断面尺寸、材料、长度及张力等参量对精度具有一定影响．

Discussion on Accuracy of Transmitting Displacement of Measuriny Rod of Extensometre

There are two ypes of the extensometre according to the working principle of theirs: one directly measures the parts measured positing the sensors in the holeianother indirectly measurs the same parts positing on the top of the hole,the latter has a short-coming with increasing the error of transmiting displacement. The test equipment consists of three parts:the end set,wall and measuring head. The accuracy of the transmiting displacement was investigated from five respacts: (1)linearity and sluggish error; (2) sluggish ; (3) unidirectional linearity; (4) property of small displacement 3 (5)repeatabi;itg error. In the last of the paper it was analysed that the influence of friction.section sizesand materials of the rod,measuring lengths and tension on the accuracy.