Click 
to display the Spectrometer Data Collection dialog. In the dialog you
will see a full spectrum analysis of the sample in the cuvette holder.
By default, the wavelength of greatest absorbance (peak) will be marked
with a box. Change the wavelength by clicking on the graph at the
desired wavelength. You can also highlight a range of wavelengths.
Three modes are available for data collection. The default mode is measurement vs. wavelength, with "measurement" being Absorbance, %Transmittance, Intensity, or Fluorescence. If you want to change the measurement, choose Change Units from the Experiment menu.
The column to the left of the graph lists all of the available wavelengths. When you select a point or region on the graph, the wavelengths are automatically selected. You can also check or uncheck the box for an individual wavelength to select specific wavelengths.
By default, Single 10 nm Band will be selected. This will average the readings of five nm on either side of the currently selected wavelength.
Use this option if you want to select multiple individual wavelengths. Contiguous wavelengths can be combined by selecting Combine Contiguous Wavelengths.
Select Combine Contiguous Wavelengths to average values for a wider band of wavelengths (such as 20 or 25 wavelengths).