Malvern Zetasizer Nano Series, Руководство пользователя

Страница: 135 / 256

default . Automatic measurements will be divided into a number of runs of at
least 10 seconds in length.
Using Manual the time may be reduced for the measurement a latex standard, or
increased to improve the repeatability of the measurement of particularly
polydisperse samples. Manually set run durations can be set between 1 and 600
seconds. The number of runs from 1 to 600. Longer measurement durations will
increase the quality of data obtained and will generally give better results, as those
runs that contain the poorest data will be rejected, with the remaining good runs
used in the final measurement calculation.
'
N o t e
. If repeat measurements with the Manual setting still show differences
in the distribution with an increased measurement time then the sample
preparation method should be reconsidered, as large particles may be
disrupting the measurement.
- Measurements
This option allows a sample to be measured more than once; possibly to
investigate the effect on particle size over time, or to prove repeatability. Set the
Number of measurements to that required. Add a delay between
measurements in the Delay between measurements text box if required.
The Append measurement number… check box will append an incremental
number, i.e. 1, 2, 3 etc, to the record name for each measurement made. The
incremental number is reset back to 1 each time the SOP is started.
.
Advanced
The Advanced dialogue contains functions to alter the cell and attenuator
position settings. For normal operations both will be at the default setting.
Measurement Position
Typically the measurement position that is automatically determined by the
software will be appropriate for most sample measurements. In certain
circumstances it may be beneficial to fix the position to reduce the total
measurement time, or establish a precise cell position for subsequent
measurements of the same sample.
By changing the cuvette position the effect of performing a measurement at
different positions within the cell can be investigated.
Attenuator
Fixing the attenuator setting can be used to enable the count rates of two samples
C H A P T E R 9
Z e t a s i z e r N a n o S e r i e s
P a g e 9 . 1 5