PN A51387A
B
6-13
Analyzing a Sample
Sample Analysis Variations
6
Determining Particle Concentration Using Time Mode
Because of stabilizing time before analysis and finishing time after, the volume of electrolyte that
passes through the aperture is more than total analysis electrolyte. To calculate the amount of
electrolyte used during the analysis run, you could do 30-, 60-, and 90-second runs and calculate the
pre- and post-run volume, which will remain the same for every analysis length.
If you are measuring particle concentration using an aperture tube 360 µm or larger, it is necessary
to use time mode. Using volumetric mode is not possible because the maximum volume allowed by
the metering pump is 2 mL. In larger aperture tubes, this volume of fluid passes through the
aperture too quickly to provide accurate statistical results.
NOTE
The Multisizer 4 uses small amounts of electrolyte for pre- and post-analysis stabilization. As a
result, calculated volume is approximate.
NOTE
If you are measuring heavy particles, Beckman Coulter recommends that you thicken the
electrolyte to increase particle suspension, reduce the flow rate, and produce less noise.
Recommended thickening agents include glycerol and sucrose.
To determine particle concentration using time mode:
1.
Fill the beaker to approximately 9/10 of its capacity and measure the exact amount of
electrolyte you will be using. Place the beaker on the platform.
2.
If you have already loaded an SOP (page
), select
SOP > Remove the SOP
on the Main Menu
bar. Removing the SOP allows you to change Standard Operating Method Settings.
3.
Select
SOP > Edit the SOM
on the Main Menu bar.
4.
In the Edit the SOM / Control Mode window, select Time, and then select 60 seconds.
5.
Click
(
OK
)
.
6.
Select
Run > Start
on the Main Menu bar (or click
(
Start
)
in the Instrument Toolbar).
7.
When the run is complete, measure the exact amount of electrolyte remaining in the beaker.
8.
Subtract the remaining electrolyte from the original electrolyte volume.
9.
Select
Edit > Edit Sample Info
on the Run Menu bar. In the Analytic Volume field, enter the mL
multiplied by 1000. The software automatically calculates concentration. To see particle
concentration, graph or list the number, volume, or surface area per mL.
Summary of Contents for Multisizer 4
Page 12: ...xii List of Figures ...
Page 14: ...xiv List of Tables ...
Page 22: ...PN A51387AB xxii Introduction Before You Start Warnings and Cautions ...
Page 42: ...PN A51387AB 1 20 Analyzer Overview Preparing the Analyzer for Sample Runs ...
Page 160: ...PN A51387AB 6 16 Analyzing a Sample Using Blank Runs ...
Page 232: ...PN A51387AB 10 8 Regulatory Compliance Additional Security Features ...
