PerkinElmer OilExpress 4, User Manual

Page: 83 / 152

Getting Started with OilExpress 4 . 83
11. If you are using a spectral-subtraction method, click in the next cell (in the Reference
Spectrum column) and then click the
Browse
button .
The Reference Spectrum Database dialog is displayed.
Reference spectra are optional in configurable methods and should not be used for
direct-trending methods. If you do not require a reference spectrum, this column can be
left blank, or hidden.
In previous versions of OilExpress, the reference-spectrum function was sometimes
used to carry out empty-cell subtraction to ensure accurate results for direct-trending
methods. This is no longer necessary, as you can select an empty cell spectrum to be
subtracted for each flow cell on the Spectrometer Setup dialog. Refer to
Empty Cell
Spectrum
on page 105 for more information.
NOTE: For more information about reference spectra, including how to collect a new
reference, and details of the analysis methods provided, refer to the OilExpress 4
on-screen Help.
12. Click on a suitable reference spectrum to select it, and then click OK.
The full name of the selected spectrum appears in the table cell.
13. If you want to specify a value for the
Sampling
Height, select the appropriate option
from the drop-down list, or type a custom value in the cell.