新型电容电感测试仪校准装置的设计与实现

Design and implementation of a new calibration device for capacitance and inductance tester

针对使用电容器和电抗器对电容电感测试仪进行校准时面临的校准程序复杂、维护成本高、误差过大的技术问题,设计了一种新型电容电感测试仪校准装置。该校准装置包括档位自动切换模块、输出比例控制模块、移相切换模块、电流放大调整模块及控制模块,通过将测试仪需要测量的电容值与电感值转化为电压电流的相位关系实现标准值的溯源。设计中依据电流输出范围将标准值划分为7个档位且各档位间自动切换,可以有效提高校准精度。实验测试结果表明,电流放大调整模块输出电流的稳定度可达到10^(-4)量级,对其在2与20 V输入电压下电容量及电感量标准值的测量不确定度分别进行评估,校准电感量与电容量相对扩展不确定度均优于0.15%,证明其测量不确定度满足设计要求。

Aiming at the technical problems of complicated calibration procedures,high maintenance costs,and excessive errors faced when using capacitors and reactors to calibrate capacitance-inductance testers,a new capacitance-inductance tester calibration device is designed in this paper.The calibration device includes a gear automatic switching module,an output proportional control module,a phase shift switching module,a current amplification adjustment module,and a control module,which realizes the traceability of standard values by converting the capacitance and inductance values to be measured by the tester into the phase relationship of voltage and current.In this design,the standard value is divided into seven steps according to the current output range and automatically switched between the steps,which can effectively improve the calibration accuracy.The experimental test results show that the stability of the output current of the current amplification adjustment module can reach the order of 10^(-4),and the measurement uncertainties of the standard values of capacitance and inductance at 2 and 20 V input voltages are evaluated separately,and the relative expansion uncertainties of the calibration inductance and capacitance are better than 0.15%,which proves that the measurement uncertainties meet the design requirements.