For each channel, you can select which of the two solvents to deliver. You can set the percentage of solvent B to any value from 0 through 100 %. Solvent A always delivers the remaining volume: 100 - %B. The solvent B check boxes allow you to turn the solvent B channels on (marked) or off (cleared).
The text boxes allow you to type a brief description of the solvents.
You can click the down arrow and select a Flow Sensor Solvent calibration from the list. the list includes the predefined calibrations provided by the firmware, and the user-defined calibrations added to the Flow Sensor Solvent Calibrations Catalog, accessible from the Configuration dialog box. The Flow Sensor Solvent Calibration Values section of the Advanced Method Setup parameters shows the current solvent calibration values.