27
elements
enabling technologies for Life Science
eONE - User’s guide
Figure 23
Statistic Data
Note:
For capacitance values higher than about
17pF select the 20nA range in order to
avoid amplifier saturation.
3.1.7
Statistic Data
The Graphical User Interface of the EDR software includes some statistical data
analysis done in real-time during the current acquisitions.
These estimated statistic data are:
Mean value
Standard Deviation (STD)
Equivalent input capacitance
Equivalent input resistance
Saturation
The
mean
and
Std
values are calculated in real-time. The input acquired data are
split in temporal windows whose length is dependent on the estimated input da-
ta bitrate and memorized in a buffer. Then, the mean and std values are calculat-
ed on these buffers.
When the user changes the bandwidth, there can be necessary to wait some time
to have valid estimated statistic data.
The following instructions have to be followed to obtain capacitance and re-
sistance estimations.
Capacitance estimation:
Enable the
Triangular Wave
using the check box (eONE Base version) or
apply the Protocol 1 (eONE VP or HS version);
Set the best range between 200 pA and 20 nA;
Check that the acquired current is a square waveform;
Click on the “
C estimation
” button.
Resistance estimation:
Be sure the “Triangular Wave” check box is NOT checked;
Set a Vc value between 10 mV and 355 mV;
Check that the acquired current is constant, greater than 0 A and not
saturating the amplifier;
Click on the “
R estimation
” button.
Values of estimated R and/or C can also be continuously visualized by checking
the “auto” checkbox.
If the proper checkbox is checked while data recording, the estimated R and/or C
values are saved every second in the header file (.edh, which is a text file).
The “
Saturation
” indicator means the input current exceeded the maximum or
minimum current value for the selected Range.
