CCA 3100
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because the calibration would be sensitive to small differences in the physical dimension of the
annulus. Another reason the instrument is not calibrated to display a discrete charge value is that
the instrument is sensitive to differences in charge distributions that vary from simple systems to
complex systems. However, the unit includes a sensitivity adjustment (HI or LOW) that
amplifies the original signal activated by the switch located on the face plate.
Figure 3 also suggests how the processing of an alternating current signal from the sensor serves
to eliminate any extraneous currents. Suppose the entire signal is moved upward a certain
amount due to an interfering current which is constant in value. When the signal is rectified, the
positive peaks remain at a higher level, but the negative peaks are at a lower level when they are
“flipped” to the positive side. After this rectified signal is smoothed, the overall result is to
eliminate the interference, since half of the peaks were too high and half were too low.
FIGURE 3
Streaming Current Processing Steps
Summary of Contents for CCA3100
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