“…In addition, by measuring the impedance value of the oil, MIS measuring can determine its electrical conductivity. Usually oil has insulating properties, but when the oil contains moisture, salt, or other conductive substances [ [9] , [10] , [11] ], its conductivity will increase. This change can be detected by impedance spectroscopy and used to assess the purity and contamination of the oil [ 12 , 13 ].…”