Surface zeta potential cell
Chapter 3
Zetasizer Nano accessories guide
Page 3-9
Hold the base of the SZP cell cap and the top of the cuvette simultaneously
.
Ensure the white marks
on the cap and cell body, and the cuvette triangle
, are facing the front of the instrument and push the cell into the cell holder
until it stops - a 'stop' on the surface potential cell must rest on the top of the
cell holder. Check that the cell is sitting flat, and that the cuvette is also
fully
inserted and rests on the base of the cell holder.
Fine alignment using the Count rate meter
A final fine adjustment of the zero-position can be made once the cell has been
placed into the instrument; this is done using the
Count rate meter
in the Zeta-
sizer software.
From the main menu select
Tools-Count rate
meter
to open the count rate
meter, and set the count rate meter as specified:
Select the
Forward scatter
radio button.
Under
Cell type
, select
ZEN1020 plate cell
(Surface zeta potential cell)
from the drop down list.
Set the
Attenuator
to
11
.
To identify if your sample is aligned correctly open the instrument lid and rotate
the cell cap
clockwise
in increments of approximately 1/8 to 1/4 of a turn. Close
the lid and observe the count rate measured in between each increment. Once you
lower the sample far enough that the
count rate
observed is
zero
, open the lid and
rotate the cell cap
counter-clockwise
by approximately 1/8 to 1/4 of a turn. Close
the lid and observe that the
count rate
has
risen
a reasonable extent. This position
is the starting point for your measurement.
For ease of reference, it is now possible to loosen the thumb screw on the
micrometer and rotate it to the front of the cell then retighten it to proceed with
measurement.
Note
After the fine alignment step, whenever the cell height is adjusted during
the experiment, it is imperative that the physical position of the cell is not
moved within the cell holder. Any movement of the cell will result in a dif-
ferent zero height and this must be constant throughout a given measure-
ment. Any alteration of the height during an experiment will reduce the
quality of the data.
