abc ABC-MEMS, User Manual, Page: 34 / 43

User’s Manual 33
8.5.4 Avg Mode
The Averaging Mode can be chosen from several choices:
•
RMS Averaging RMS averaging reduces signal fluctuations but not the noise floor.
The noise floor is not reduced because RMS averaging averages the power of the signal.
RMS Averaging is the most common type.
•
Peak-Hold Peak hold averaging retains the peak levels of the measured spectra.
Peak hold averaging is performed at each frequency line separately, retaining peak levels
from one FFT record to the next.
Note: All the FFT calculations are performed on the PC. The raw time-signals are transferred from
the instrument to the PC, where the FFT and averaging calculations are performed.
8.5.5 Scale
The power spectra can be displayed in g or m/s
2
scale for acceleration, and in m/s for velocity. The
scale can be chosen linear or dB. Changing the scale does not restart the averaging It just displays the
same data in a different scale.
8.5.6 Cursor, Zoom and Pan
A cursor can be used to precisely measure the frequency and amplitude of a particular spectral point. In
order to use the cursor proceed as follows:
•
Press on the button that looks like a cross (see Figure 11 (1))
•
Place the mouse over the point where the X and Y cursor lines meet and left-click. This grabs
the cursor.
•
Drag the cursor to the spectrum curve and frequency of interest. The cursor can jump from
one curve to the other.
•
Read the X and Y values in the cursor field underneath the graph.
Zooming and Panning is done the same way as in the Records graphs. See section Graph Controls .
The auto-scale button can be pressed or released to obtain an automatic or fixed scale. When the
graph is in fixed scale, writing directly in the values of the end-scale markers sets the scale to fit those
values, in the X as well as Y scales.
8.6 Static Tab
The static tab is seen in Figure 12 . It displays the measured static acceleration along the three axes.
This can be used to verify the calibration. When a particular axis is vertical and the instrument is not
moving, the measured static acceleration along that axis should be precisely 1g.
The static tab also shows a graphic depiction of the instrument’s inclination, as well as the tilt angles
around the X and Y axes.
8.7
WiFi
Tab
The WiFi tab has all the indicators showing the instrument’s present state of connection, as well as
controls to configure WiFi™ and email settings.