System includes a sensor operably coupled to a device body. The sensor includes a sensing region and at least one resonant inductor-capacitor-resistor (LCR) circuit. The sensing region is configured to be placed in operational contact with an industrial fluid. The at least one resonant LCR circuit is configured to generate an electrical stimulus that is applied to the industrial fluid via electrodes at the sensing region. The device body includes one or more processors configured to receive an electrical signal from the sensor that is representative of a resonant impedance spectral response of the sensing region in operational contact with the industrial fluid responsive to the electrical stimulus. The one or more processors are further configured to analyze the resonant impedance spectral response and determine both a water concentration in the industrial fluid and an aging level of the industrial fluid based on the resonant impedance spectral response.