Sequoia LISST-PORTABLE XR, Руководство пользователя

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14 LISST-Portable|XR manual
Make sure the drain lever is in the closed position and then add the sample from your beaker to
the mixing chamber. You can use the funnel to pour the sample through the hole in the center of
the mixing chamber, or you can remove the lid and pour the sample in directly. Make sure that
your sample is well homogenized and suspended before you pour it in so that you are not
introducing bias into your results.
If you press the grey ‘File Note’ box the keypad will appear, and you can enter a note with a
maximum length of 50 characters.
If the SOP is set for Automatic mode the mixer and ultrasonic automatically turns on and
prepares the sample before measurement. The screen will display the time remaining for each
step and show the current optical transmission. When the preparation is complete, the sample is
measured.
If the SOP is set for Manual mode the mixer and ultrasonic needs to be manually controlled using
the sliders on the screen. Turn off the ultrasonic when the sample is ready, but leave the mixer at
the desired speed and tap the Next button.
For both Auto and Manual Mode the optimum concentration range is shown as percent optical
transmission in the optical bar chart on the left. The transmission values should range from 75 to
95% (green part of the bar).
If your sample causes the transmission to drop to below 65% (bottom red part of the bar) you
must dilute the sample
– see the FAQ in chapter 11.
If your sample concentration is so low that the transmission is in the yellow part of the bar, above
95%, you should increase the averaging time, see section 3.2.
If you did not turn on the mixer, a warning message will appear, asking you to confirm if you
really do not wish to turn on the mixer.
Push the button to turn on the mixer and continue.
Push the button to continue without turning on the mixer.
Note: It is HIGHLY recommended that you always turn on the mixer. Otherwise your results
will be unreliable, as the particles in the mixing chamber will settle out and only be partially
measured, or not measured at all!
If the optical transmission is below 65% a warning message appears.
If you wish to continue, push the button, otherwise push the button and try diluting the
sample.