| 摘要 |
<p>The invention provides apparatus for measuring the AC electrical parameters of a sample, such as an electric component, electric network, material when dry or in liquid, the apparatus comprising a generator for generating a pseudo random binary sequence, a digital to analogue (D/A) unit or equivalent, or other means to output the sequence in digital or analogue format, first connection means for connecting the output of the generator to the input of the D/A, sample input connection means adapted to apply the output of the D/A to the sample, sample output connection means for connecting a sample output to an analogue to digital converter (A/D) or equivalent, and an output processing unit being configured for subjecting the output of the A/D to a Hadamard Transform followed by a Fast Fourier Transform (FFT) for producing in use a measurement of the complex impedance frequency response of the sample . The inventive apparatus can acquire the impedance frequency spectrum (calculated from the measured transfer function) of a system in a very short time, typically 1 microsecond to 5 seconds.</p> |
