Waters 2489, Operator'S Manual

Page: 125 / 234

Scanning spectra 3-57
4. Press Enter to exit the information screen and return to the Scan choice
list.
Reviewing a stored spectrum
Once you have stored a spectrum, you can retrieve it for review from one of the
five available storage slots by selecting the Review option from the Scan choice
list.
To review a spectrum:
1. Press SCAN (Shift Chart Mark) to view the Scan choice list.
2. Press 4, Review.
Tip: When you select Review, you actually are retrieving the zero scan
and the sample scan that were stored as a pair.
3. Enter the storage slot number (1 to 3) of the spectrum you want to
review.
4. Press Enter. The message “Retrieving spectrum n” appears.
After a brief wait, the stored spectrum appears.
Once you retrieve a spectrum for review, you can view it graphically and
adjust the wavelength and AU ranges, if necessary. You can also run a new
sample scan based on the retrieved zero scan.
Subtracting a spectrum
Once you have stored more than one spectrum, you can create a difference
spectrum.
Tip: The current spectrum is the spectrum being subtracted from; the stored
spectrum whose slot number you enter is the spectrum being subtracted out.
To subtract and review the difference spectrum:
Rule: To subtract one spectrum from another, the starting and ending
wavelengths (
λ
1 and
λ
2
)
and the pace of both spectra must be identical.
1. Press SCAN (Shift Chart Mark).
2. Press 5, Subtract & review.