Sinusoidal fitting using exact linearization applied to bioimpedancimetric measurements

Microbial growth can be continuously followed up by measuring the interface impedance Z/sub i/ of two electrodes immersed in a culture medium. A new method based on sinusoidal fitting is used to reduce measurement errors. It applies an exact linearization with which it is possible to obtain a linear relationship of the parameters to be estimated. This permits the application of the least squares procedure, producing pure sinusoidal waves, which greatly reduce the error in the determination of the interface impedance amplitude and phase components.