A probe assembly and method is disclosed which includes a plurality of sensors for respectively mreasuring predetermined attributes of a fluid. The probe assembly comprises a first sensor for measuring the quantity of the fluid. The first sensor includes a capacitive reference cell and a capacitive product measurement cell, each of the cells being characterized by respective associated capacitances. In particular, the capacitance associated with the capacitive product measurement cell varies in accordance with the quantity of the fluid so that the quantity of the fluid is indicated by the quantitative relationship between the magnitude of the capacitance associated with the capacitive reference cell and the magnitude of the capacitance associated with the capacitive product measurement cell. A second sensor extends coaxially at an extremity of the reference cell and includes a conductive portion to be at least partially immersed in the fluid so that the conductive portion of the second sensor is operable to effectively form a capacitive element with the fluid and with an extraneous conductive element. In this manner the capacitance of the capacitive element is determined by the characteristics of the fluid. A third sensor in the form of a thermistor is disposed in the reference cell for determining the temperature of the fluid. A liquid overflow detection device and method is also disclosed.