At least one property of a complex liquid is determined utilizing first and second sensing devices for measuring a respective first and second physical parameter of the liquid and generating respective first and second measured data indicative thereof. A control unit connectable to the sensing devices is used for analyzing the first and second measured data and determining the at least one property of the complex liquid. The first measured data may be responsive to a relatively low-frequency electric or electromagnetic field induced in the liquid, and the second measured data may be a response of the liquid to a relatively high-frequency external electromagnetic field applied to it.
