This section applies only to the VH-D20 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:
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.
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).