Abstract: The present invention discloses an apparatus for detecting one or more fluids, the apparatus comprising a sensor means having electrical properties dependent upon one or more of the presence and the concentration of one or more fluids, an electrical excitation means for applying one or more electrical excitation pulses to the sensor means, a detector means for detecting the electrical behavior of the sensor means in response to the electrical excitation means, and a transformation means for transforming an output of the detector means from the time domain to the frequency domain to determine the electrical properties of the sensor means as a function of frequency over a pre-determined frequency range.