Optimizing hardware
PlasmaQuant MS product family
64
5.
Make a note of the present
DETECTOR VOLTAGE
. You need to compare this value to
the recommended voltage in a later step.
6.
Click [S
TART
].
The PlasmaQuant MS scans the detector voltage across the scan range shown in
the F
ROM
and T
O
boxes in the lower-left (e.g. from 1500 to 3500 Volts).
When the scan is finished, the software calculates a curve-fitting algorithm on the
signal obtained, and determines the recommended operating voltage.
7.
Click [OK] to display the recommended voltage in the
DETECTOR VOLTAGE
box at the
bottom of the display.
8.
If you want to change the detector voltage to the recommended setting, click
A
PPLY
. Generally, if the recommended voltage is >200 V different than the previous
setting, you should update the detector voltage to the new recommended setting
and re-do the attenuation if applicable (see Chapter 9 for more information on
detector attenuation procedures).
6.6
Detector attenuation
The detector operates across a wide dynamic range (11 orders of magnitude) by
attenuating high-level signals so they are always within its operating range. The
attenuation system must be calibrated by measuring low and high concentrated
standards of every element (isotope) that is to be analyzed.
The attenuation factors should be checked routinely once or twice a year. Every time
the detector operating voltage is changed, the attenuation factors must be confirmed
as well. Attenuation factors are stored independently of any worksheet. After the
attenuation values have been created for a specific detector voltage, they can then be
applied to any sample matrix or condition set.
A detailed procedure for calibrating the detector for extended range mode
(attenuation) is found in section 9.
Fig. 31 Setting up detector attenuation