Biotage ELSD-A120, Руководство пользователя

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32 Biotage
®
ELSD-A120 User Manual
4
Using the Detector
Operational Parameters
Evaporator Gas Flow
The evaporator gas flow is used to control the detector’s evaporation
process. The evaporator gas value is set according to the mobile
phase composition, with higher gas flows (e.g. 1.6 SLM) being used
for aqueous eluent compared to those containing organic solvents.
The higher the evaporator temperature the lower the evaporation gas
setting required (e.g. 1.0 – 0.9 SLM), regardless of mobile phase
composition. Likewise, as the evaporator temperature is reduced to
an ambient temperature, the gas flow needs to be increased to
compensate (e.g. 1.6 – 1.8 SLM).
The evaporation gas range is 0.9 – 3.25 SLM (0.05 increments).
The default value is 1.6 SLM.
Detector Gain (PMT)
The detector gain parameter sets the factor by which the detector
output signal is amplified. The gain setting does not change the
sensitivity of the detector, but merely amplifies the captured signal by
the inputted factor. The gain can be adjusted from 1 to 10 in
increments of 0.1.
When setting the PMT (or Gain), both the signal and noise are simply
amplified by the value set, so S/N values are unaffected. The raw
signal output displayed on the parameter screen will reflect this
increase or decrease in signal amplification.
Please note that the detector output displayed on the main operating
screen does not alter following a PMT change, thus the recorded
baseline position will remain unchanged. Confirmation of a PMT
change will be obvious by the change in baseline noise.
Response Time (Smoothing)
The data outputted from the detector can be averaged to produce a
smoother response. The smoothing width is set to the number of data
points over which the data is averaged and can be regarded as a digital
time constant. The smoothing range is 1
– 50
, (in increments of 1),
which translates to 0.1 – 5.0 s.
For flash applications a value of 50 (5 seconds) is satisfactory.