纯弯矩梁型应变计灵敏系数测定装置的误差分析和精度评定方法（一）

为检定纯弯矩梁型应变计灵敏系数测定装置的精度。国际上６０年代 以来都是从应变定义出发，总想直接测定标定梁表面的准确应变值。由于测量原理不理想和仪表分辨精度不够高等因素，一直未得到较理想地解决。

Error Analysis and Method of Accuracy Evaluation of Strain Gauge Factor Testing Apparatus Based on Pure Bending Moment Beams

For the appraisal of accuracy of strain gauge factor testing apparatus based on pure bending moment beams, the common means adopted since the 1960s and still in use internationally today are by application of the strain definition to measure directly the strain on the calibration beam surfaces. However, because of the imperfect measuring principle and inadequate resolution and accuracy of instruments available, etc., this problem has not been solved satisfactorily. This paper proposes a unique way by introducing two new concepts, i.e., the shape errors of the cylindrical surfaces and deflection errors of the bent calibration beam, in accordance with the features of the forces acting on the beam, and the geometric shape and dimensions of the beam in operation, to analyse and classify the various accidental and systematic errors involved. Through the two concepts, the task of appraisal of accuracy is simplified as the evaluation of uncertinty of the cylindricality of the cylindrical surfaces and the deflection of the bent calibration beam.The paper proposes "the moving tri point type cylindrical surfaces micrometer",combined measureing overall shape errors of the bent calibration beam.Its relative expanded uncertainty is U r=0 013% when coverage factor K=3.