Abstract: A method for analyzing a dielectric medium comprises the step of measuring, at one or more frequencies, the capacitance between a pair of electrodes immersed in the dielectric medium. The proportion of the or each capacitance measurement due to electrode polarization capacitance and/or to the residual capacitance of the dielectric medium is then determined using capacitance measurements made between the electrodes at a first frequency and at a second frequency, the ratio of the respective polarization capacitances at these two frequencies being predetermined. An apparatus for performing the method is also disclosed.

Abstract: A method and apparatus for analysing a sample, in which a neural network is trained to correct for measurement drift of a given analytical instrument (e.g., a mass spectrometer). The training is carried out using first and second sets of data obtained by the instrument from samples of known compositions at initial and subsequent instants of time, respectively. The trained neural network is used to transform data, obtained by the instrument from a sample of unknown composition at said subsequent instant of time, to an estimate of the data which would have been obtained by the instrument from that sample at the initial instant of time. The transformed dasta is then analysed to analyse the sample of unknown composition.