精密交流数字电桥准确度分析

针对精密交流数字电桥计量与使用过程中,行业内普遍采用基本准确度作为仪器最终技术指标的现状,研究分析了精密交流数字电桥原理及影响测量准确度的因素。详细阐述了数字测量仪最大允许误差的计算方法,以E4980A为典型型号给出了电容参数"逐点计算方案",相同测量点的计算结果较传统的计算方法最大相差±11.95%,结果表明所提计算方法能够作为交流数字电桥评价性能指标的准确手段,更好地指导用户正确使用每一个测量点的技术指标,同时避免造成计量人员的误判,具有更高的实用性。

Accuracy analysis of precise digital measuring instrument

In view of the current situation that the basic accuracy is generally adopted as the final technical indicator of the instrument in the process of measuring and using precise digital measuring instrument,the paper has analysed the principle of precise digital measuring instrument and the factors that affect the measurement accuracy,elaborated the calculation method of the maximum permissible errors of the digital measuring instrument in detail,and proposed the"point-by-point calculation scheme"of capacitance parameter by taking E4980 A as a typical model.and finally found the calculation result of the same measurement point is±11.95%different from the traditional calculation method.The result shows that the calculation method in this article can be used as an accurate method for evaluating performance indicators of AC digital bridges,which can better guide users to correctly use the technical indicators of each measurement point.At the same time,it can also avoid the misjudgment of measurement personnel and has a higher practicability.