If wavelengths are switched during a single-channel data acquisition, the chromatogram may show baseline jumps.
You can define how the baseline behaves in these cases:
Zero: sets the baseline to zero
Append: appends the baseline to the previous signal
Free: lets the baseline "jump" to the current absolute value
TIP
You can perform the AutoZero command (automatic null balancing) any time during data acquisition, that is, the absorption measured at the time of the autozero is subtracted from any absorptions measured thereafter. Always select a time for AutoZero at which no sample flows through the cell.