Beckman Coulter Multisizer 4, Руководство пользователя

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PN A51387A
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3-10
Installing and Calibrating an Aperture Tube
Calibrating the Aperture
Calibrating the Aperture
When you calibrate the aperture, the Multisizer 4 runs an analysis to measure calibrator beads of a
predetermined size (ranging from a nominal modal value of 2 µm to 400 µm). Calibrate the aperture
with a particle standard that is 10% to 20% of the aperture size (20% is preferred).
Variations in the Analyzer’s measurement of the calibrator beads determine the calibration
constant (Kd) required for the Analyzer to measure the beads at their actual size.
The Kd takes into account many factors associated with the instrument and the aperture tube,
including fluid flow characteristics, electrical resistance with the electrolyte, and imperfections of
the orifice such as chip damage or wear.
When you verify aperture calibration (page 3-18 ), the Multisizer 4 Analyzer 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, which
returns a calibration constant (Kd) for the aperture orifice, the verification procedure returns the
measured calibrator bead size.
NOTE
Calibration options are only available to user types with sufficient security privileges. If the
Multisizer 4 software is running with no security, every operator can calibrate the aperture, create
an SOP, and configure the software.
Calibrate the aperture after you:
1. Select a new aperture tube size (page 3-1 )
2.
Install the new aperture tube (page 3-2 )
Choosing the Calibrator Size
Before you calibrate the aperture, use the table below to choose the appropriate calibrator size.
Beckman Coulter recommends that you calibrate the aperture with a particle standard that is 10%
to 20% of the aperture size (20% is preferred).
The calibrator beads supplied with the Multisizer 4 Analyzer are suitable for use with a 100-µm
Aperture Tube.
Table 3.2 Choosing Calibrator Size
Aperture Size (µm) Calibrator Mean or
Modal Size (µm)
20 2 – 4
30 3 – 6
50 5 – 10
70 7 – 14
100 10 – 20
140 14 – 28