Malvern Zetasizer Nano Series, User Manual

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As soon as a run is completed the result tab changes to blue to indicate a
preliminary size result is available to view (by clicking on the tab). As more runs
are made and assessed the quality of the result will improve.
Molecular weight measurements
The molecular weight measurement sequence requires a series of intensity
measurements to be made, first of a standard to establish the reference scattering
intensity, and then of each of a number of prepared sample concentrations. At
each part of the sequence the user will be prompted for the insertion of the next
concentration. As this requires more interaction than for size and zeta potential
measurements, the sequence has been described below
.
Press start to begin the dark count measurement.
The laser is turned off and a measurement is taken of the background light
level.
.
Insert the scattering standard cell (i.e. Toluene) and press start when ready.
The measurement will measure the scattering intensity of the scattering
standard used.
.
Once the standard has been measured a dialogue box will appear to prompt
insertion of the first sample concentration (i.e. the pure solvent). Insert the
first sample concentration and press
start .
.
The software displays another dialogue where the sample concentration can
be entered. Type in the concentration and press
enter
.
The measurement continues.
.
On completion of the first sample measurement, a dialogue is displayed -
answer
Yes
to “Repeat measurement of concentration 1?” or
No
to con-
tinue with the second concentration.
.
Continue as above until all sample concentrations have been measured.
.
On completion of the last concentration the final result will be calculated.
The progress meter indicates the measurement progress during each stage.
Zeta potential measurements
The cell is inserted and Start is pressed. The cell is first checked to identify the
cell type fitted, and that it agrees with that selected in the SOP. Once identified
the measurement sequence continues automatically. The status bar will indicate
the instrument is now “
Performing the measurement ”.
Each complete measurement is divided into a number of measurement runs .
All the individual measurement runs are accumulated together and then summed
to give a final
Zeta result .
C H A P T E R 4
Z e t a s i z e r N a n o S e r i e s
P a g e 4 . 2 2
M A N 0 3 1 7