ORTEC Easy-MCS, Hardware User Manual

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931054C / 1213 6. MENU COMMANDS
49
Fig. 37. Calculate
Menu.
Fig. 38. Set the Peak Search
Sensitivity.
In Fig. 36, a signal with an amplitude of approximately 5 V has been fed into the SCA input. The
spectrum peak collected has been marked in reverse video by clicking and dragging the mouse
from one side of the peak to the other. The voltage range of this marked region is reflected in the
Voltages field in the dialog (note that the Channels and Voltages fields in the SCA Sweep
dialog will update in real time as you click and drag the mouse). These SCA voltages correspond
to the upper and lower limits of the region marked on the peak. To set the SCA levels to these
voltages, click the Set SCA button. The SCA sweep will run faster if the range of sweep volt-
ages is limited. To do this, click and drag the marker over the range of channels to be swept and
click the Set Range button.
The Full Button returns the range to 10 V. The Stop Button stops acquisition. The Start Button
restarts the acquisition and Clear Data clears the data. The Cancel Button can be used to exit
the SCA sweep mode and return the SCA settings to their original values.
6.3. Calculate
The Calculate menu is shown in Fig. 37. These commands
functions are available in both MCS and buffer mode.
6.3.1. Settings...
Settings... opens the dialog shown in Fig. 38, which allows
you to set the sensitivity of the algorithm used in Peak Search.
Duringa peak search, suspected peaks in a spectrum must pass
a sensitivity test to be accepted. This test compares the magni-
tude of the smoothed second difference with the weighted error
to be accepted. The peak search sensitivity is a multiplicative
factor in the weighting factor.
Use the Peak Search Sensitivity slider to set the sensiti-
vity to a value between 1 and 200. A value of 1 is the most
sensitive (i.e., finds more peaks), and 200 is the least sen-
sitive (i.e., fewer peaks will be found). Click and drag the
slider to the setting you want. To make finer adjustments,
click the slider bar to activate it, then use the <
8
>/<
9
>
keys.
Click OK to activate the new settings.