空腔中B-dot低频特性的硬件补偿

Hardware compensation of B-dot low frequency characteristics in cavity

针对在空腔中的微分环(B-dot)探头输出信号存在低频增益的问题,分析了目前使用的"磁通穿透特征时间常数"一阶修正方法,提出了使用适当积分常数的积分器进行补偿的方法。对安装在同轴线及径向线电极孔中的B-dot进行实验,结果表明:当积分器的积分时间常数等于磁通穿透特征时间常数时,B-dot的测量结果与标准电流信号吻合。因此这也是空腔中的B-dot探头选取积分器的原则。该方法使用硬件直接获取了补偿后的测试结果,与软件修正方法比较操作较为简便。

The output signal of B-dot probe in the cavity increases at low frequency.The first-order correction method of“a characteristic flux-penetration time”is analyzed.According to the analysis,the method of compensation with integrator is proposed.Frequency response experiments were carried out for B-dot installed in the electrodes of coaxial and radial lines.The results show that when the RC time constant of the integrator is equal to the characteristic flux-penetration time,the measurements of B-dot coincide with the standard current signal.Therefore,for the B-dot probe in the cavity,this is the principle of selecting the RC constant of the integrator.The compensated test results are obtained directly by hardware,thus it is more convenient to operate than the software correction method.