In recent years, impedance measurement method by piezoelectric (PZT) wafer activesensor (PWAS) has been widely adopted for non-destructive evaluation (NDE). In this method, theelectrical impedance of a bonded PWAS is used to detect a structural defect. The electro-mechanicalcoupling of PZT materials constructs the original principle of this method. Accordingly, the electricalimpedance of PWAS c...

A cell-impedance measurement system is presented that can measure an effective parallel resistance and capacitance of a cell to within 1% in 1ms. It is proven to be functional at ten logarithmically-spaced frequencies between 100 kHz and 100 MHz, with ten parallel structures simultaneously calculating each of these. This system is further shown to be implementable with commercial parts – namely...

Bioelectrical impedancemetry (BIA) has been used to evaluate hematocrit and red cell aggregability in vitro but whole body impedance measurements are also correlated to some hemorheologic factors, suggesting a relationship between viscosity factors and electric properties of blood. We repeatedly reported correlations with whole body BIA and hematocrit, whole blood viscosity and plasma viscosity...

In order to measure the impedance variation process in electrolyte solutions, a method of triangular waveform voltage excitation is investigated together with principal component analysis (PCA). Using triangular waveform voltage as the excitation signal, the response current during one duty cycle is sampled to construct a measurement vector. The measurement matrix is then constructed by the mea...

The electric-pulse-induced resistance switching in layered structures composed of polycrystalline Pr1-xCaxMnO3 (PCMO) sandwiched between Pt bottom electrode and top electrodes of various metals (metal/PCMO/Pt) was studied by direct current current-voltage (I-V) measurements and alternating current impedance spectroscopy. The I-V characteristics showed nonlinear, asymmetric, and hysteretic behav...

In this paper we describe a system which we have developed to measure cat ear canal specific acoustic impedance Zsp, magnitude and phase, as a function of frequency, for frequencies between 200 Hz and 33 kHz, and impedance magnitude between 4.0 to 4.0×105 [Rayles] (MKS). The object to be measured is placed at the end of a 3.5 mm diameter sound delivery tube. After a simple calibration procedure...

Development of appropriate models for the interpretation of impedance spectra in terms of physical properties requires, in addition to insight into the chemistry and physics of the system, an understanding of the measurement error structure. The time-varying character of electrochemical systems has prevented experimental determination of the stochastic contribution to the error structure. A met...