A practical grounding resistance measurement method
Xiao Zhang · Dianli zidonghua shebei · 2002
Dual frequency technique is discussed based on the basic grounding resistance measurement method.In order to eliminate the power frequency interference,two cureent sources with different frequency are used in grounding resistance measurement.The best frequency ranges for the two sources are selected,the lower one is from 15 Hz to 30 Hz and the other is from 60 Hz to 120 Hz.The hardware architecture for implementing the measurement technique is introduced. Two measuring signal sources with different frequency are generated one after another by CPU,the measured values are acquired with the measuring unit and the grounding resistance is then calculated.It shows that this technique is simple and practicable with strong anti interference capability and high measurement accuracy