Agilent InfinityLab ELSD User Manual
49
4
Using the Module
Operational Parameters
Nebulizer Temperature
The nebulizer temperature can be used to optimize signal response in addition to
evaporator temperature. Higher nebulizer temperatures increase peak response,
but the nebulizer temperature must not exceed the boiling point of the mobile
phase.
The nebulizer temperature range for both models is: OFF, 25 – 90 °C (1 °C
increments).
The default value is 40 °C.
Evaporator Gas Flow
The evaporator gas flow is used to control the ELS 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 ambient and subambient
temperatures, the gas flow needs to be increased to compensate (e.g.
1.6 – 1.8 SLM).
The evaporation gas range for both models is: 0.9 – 3.25 SLM (0.05 increments).
The default value is 1.6 SLM.
Detector Gain (PMT)
This 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 instrument 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.
