Beckman Coulter Multisizer 4, User Manual

Page: 72 / 238

PN A51387A
B
3-18
Installing and Calibrating an Aperture Tube
Verifying the Calibration
3. In the Select Aperture Tube window, click
(
Edit List
)
. The Edit Aperture Tube List window
opens.
4. In the Edit Aperture Tube List window:
a. In the Diameter/Serial Number/Kd/Comment box, click the row you want to edit.
b. Enter the new mean Kd in the Kd field.
c. Click
(
Update
)
.
d. Click
(
OK
)
to return to the Select Aperture Tube window.
NOTE
If you enter a Kd value that is too low or too high for the expected operation, the software
will display a warning message.
5. In the Select Aperture Tube window:
a. In the Diameter/Serial Number/Kd box, click to highlight an Aperture Tube.
b. Click
(
OK
)
to return to the Wizard.
6. Click
(
Close
)
to exit the Wizard.
Verifying the Calibration
When you verify aperture calibration, the Multisizer uses the Kd (or the mean Kd, if you have
obtained 10 Kd values and calculated the mean) to verify that the instrument is measuring
calibrator bead size accurately. Unlike the aperture calibration procedure (page
3-13 ), which
returns a calibration constant (Kd) for the aperture orifice, the verification procedure returns the
measured calibrator bead size.
Because the Analyzer uses constant current, the instrument holds the calibration for an indefinite
time, provided that the working conditions are stable and you are using the same aperture tube and
electrolyte combination. If working conditions are not stable, you can select an option to prompt