Elekta Neuromag NM21283A, Руководство пользователя

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8 Basic measurements
46 NM21283A-A
8.4 View modes
In most cases the result of a measurement can be displayed in several for-
mats, or different aspects of the result can be shown. For each measure-
ment/job there are two principal displays. One showing all channels and
another showing one specific channel. Typically the data shown for all
sensors are somehow compressed.
To select the overview (all channels), set the active channel to 0. To show
some particular channel, select the channel either by clicking the bar rep-
resenting it or by using the operating point controls. See “Noise display”
on page 15.
Specific measurement results can be selected for viewing from the
View
menu. The displays that are associated to each measurement mode are
listed in the description of each mode.
8.5 I-Phi measurement
The I-Phi job measures the flux versus current characteristics of all sen-
sors. It can average several measurements and the data is arranged so that
it is possible to estimate factors like feedback voltage corresponding one
, modulation depth etc.
If these characteristics are needed for manual tuning purposes, use “Man-
ual tune” instead. It performs the same measurement without any averag-
ing showing the raw x-y data. The basic I-Phi job is rarely used manually,
however the measurement is used as a building block in several other jobs,
so that adjusting the parameters in “I-Phi measurements” does affect sev-
eral other jobs.
The parameters affecting the I-Phi measurements are shown in table
Table 8.1.
Parameter Type Description
AveLength integer Number of x bins in x-y trace curves used
in averages.
NumAverages integer Number of averages taken.
TuneSfreq float Sampling frequency used. [Hz]
FuncAmp float Excitation amplitude. [V]
FuncFreq float Excitation frequency. [V]
Table 8.1 Parameters affecting I-Phi measurements
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