Thermo Scientific Vanquish VF-D20, Руководство по эксплуатации, Страница: 109 / 182

6 • Operation
Vanquish Charged Aerosol Detectors Operating Manual Page 109
6.7.6 Gas Regulation Mode (VH-Detector only)
This section applies only to the VH-detector.
The detector provides two gas regulation modes to optimize the
efficiency of the nebulizer: Analytical mode and MicroLC mode. Each
mode sets a specific nebulizer gas pressure for the analysis, based on the
gas pressure specified for the nebulizer from the nebulizer certificate.
To select the gas regulation mode for your application, note the
following:
• Analytical mode
♦
The pressure for the gas regulator is set to the nebulizer gas
pressure setting as defined on the nebulizer certificate.
♦
For use with high pump flow rates within the pump flow range
allowed for the detector
♦
This mode is set as a default in Chromeleon.
• MicroLC mode
♦ The nebulizer gas pressure setting is automatically reduced by a
fixed fraction of the nebulizer pressure.
♦
This mode optimizes the nebulizer gas pressure for certain pump
flow rates and certain types of mobile phase compositions.
♦
For use with very low pump flow rates within the pump flow
range allowed for the detector
TIP The resulting nebulizer gas pressure will be below the gas
pressure specified in the nebulizer certificate (for example, below
55 psi or 3.8 bar or 379 kPa).
6.7.7 Power Function Value
The signal of the detector has a wide dynamic range with over four
orders of magnitude. The nature of the response is inherently nonlinear.
The Power Function Value (PFV) applies a power transformation to the
data output of the detector. Power transformations can improve the
linearity of response over a given range of interest.