中文摘要：

为了抑制和排除电磁流量计测量过程中的干扰,提高信噪比,提高测量的精确度和稳定性,讨论了电磁流量计几类干扰噪声产生的物理机理和特征,简要阐述了电磁流量计的几种硬件和软件方面的抗干扰技术。硬件方面设计了高精度低功耗的矩形波激磁电路,并从激磁电路中引出A/D转换器的参考电压,提高了A/D转换结果的抗干扰能力。软件方面主要采用＂计算斜率法＂和＂正负差值法＂相结合的方法消除零点漂移。实验表明,这些方法在智能电磁流量计的测量过程中取得了明显的效果。

英文摘要：

With the aim to restrain and eliminate the interference brought from the measuring process,make the signal-to-noise ratio,the precision and the stability of the system get improved,the physical mechanisms and characters concerning several kinds of interference noises derived from electromagnetic flow meter are discussed in this paper.And some anti-interference technologies applied in the electromagnetic flowmeter are summarized briefly,including the hardware and software aspects.From the hardware,a square waveform exciting circuit with high accuracy and low power consumption,and the reference voltage of the A/D conversion is got from this circuit,which improves the anti-interference ability of the result of the A/D conversion.From the software,two methods named slope calculation and positive and negative difference are used together,which help to eliminate the zero shift.All of methods above have a remarkable effect on the metrical result of the intelligent electromagnetic flowmeter.