Measurement of wave heights

The accuracy of the method depends upon the precision with which the two volumes of solution and the corresponding diffusion currents are measured. The material added should be contained in a medium of the same composition as the supporting electrolyte, so that the latter is not altered by the addition. The assumption is made that the wave height is a linear function of the concentration in the range of concentration employed. The best results would appear to be obtained when the wave height is about doubled by the addition of the known amount of standard solution. This procedure is sometimes referred to as spiking. 

With a well-defined polarographic wave where the limiting current plateau is parallel to the residual current curve, the measurement of the diffusion current is relatively simple. In the exact procedure, illustrated in Fig. 16.6(a), the actual 

It is simpler, though less exact, to apply the extrapolation method. The part of the residual current curve preceding the initial rise of the wave is extrapolated a line parallel to it is drawn through the diffusion current plateau as shown in Fig. 16.6(h). For succeeding waves, the diffusion current plateau of the preceding wave is used as a pseudo-residual current curve. 

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The wave number-frequency spectrum of wind waves was measured at low wind velocity, 2.5 m s 1, and at two different fetches. Dominant dm-cm-scale wind waves are steep enough and are characterized by asymmetric profile and parasitic ripples generation even at such a low wind velocity, so that we expect that nonlinear effects can be quite strong. Co-located measurements of wave height were conducted using a wave gauge. The... 

Numerous methods of measuring the wave height are described in the literature and a choice amongst these might seem to be a diflicult task. However, most of the methods used give essentially equivalent results, provided that the measurements are carried out with sufficient care and accuracy and that the wave height is measured in the same way for all waves to be compared—that is, for the samples thqpiselves and for the standards used in calibration. 

There are two important principles to follow in measuring the wave-height. For exact theoretical work only the measurement of... 

Fig. 35.8. Histograms documenting changes in the ranges of measured significant wave heights off the coast of Washington.

Analysis for wave data typically consists of plots of the measured surface elevation and calculations of wave height and period. Tsunamis are usually characterized by only a few wave forms, so it is relatively easy to measure the main or largest wave in the profile. These calculations are usually done in the time domain by estimating the average wave height in the record. 

Draw a tangent through the point of greatest slope of the diffusion wave and measure the vertical distance between the points of intersection it makes with the production of the flat portions of the beginning and end-points of the curve. Calculate the concentration of the gamma-isomer in the sample by the direct comparison of wave heights obtained for the sample and standard solutions and the known concentrations of these solutions. 

Fig. 1 Measuring method of echo height of side drill hole Fig. 2 Calculation Method of Echo Directivity [or SH Wave Probes...

The echo directivity for surface SH Wave probes and SH Wave angle probes was measured. The experiment was carried out by measuring the echo height from side drilled holes of different depths at a constant beam path length. The calculation of echo height was based on a point sound source on the test surface in different phases. The experiment and the calculation were compared. The effects of the frequency, height of... 

The measurement of the current for a redox process as a fiinction of an applied potential yields a voltaimnogram characteristic of the analyte of interest. The particular features, such as peak potentials, halfwave potentials, relative peak/wave height of a voltaimnogram give qualitative infonnation about the analyte electrochemistry within the sample being studied, whilst quantitative data can also be detennined. There is a wealth of voltaimnetric teclmiques, which are linked to the fonn of potential program and mode of current measurement adopted. Potential-step and potential-sweep... 

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