Waters 2475, Operator'S Manual, Page: 109 / 228

Operating the detector 3-37
Normalization values at completion
The values are used in the emission units formula described on page 1-14 . As
the lamp and optics age, the Raman Gain will gradually increase to a
maximum of 1000, and the Raman Counts value can decrease. If the Raman
signal for water occurs within 3 nm of 397 nm, the normalized units are
embedded in the detector’s memory. If the signal fails to occur within that
range, the detector does not save the values but instead preserves the prior
constants.
Tip:
If the Raman signal is not within 3 nm of 397 nm, usually something
other than pure water is in the flow cell or the flow cell is dirty.
Operating the detector in single-channel mode
The detector is optimized for single-channel ( λ) operation, the default
operating mode.
To specify single-channel mode when the detector is in multichannel mode:
1. From the home screen, select l/
λλ
(Shift, Auto Zero).
Result:
The detector displays an appropriate message while switching to
single-channel operation.
2. Enter the wavelength, gain, and sensitivity on the home screen. Also
enter any secondary parameters, timed events, or threshold events (see
the figure “Secondary functions of the home screen” on page 3-17 and
the table titled “Primary and secondary function (method) parameters”
on page 3-21 through the table titled “Threshold events “To”
parameters” on page 3-48 ).
Tip:
Changing the sensitivity (EUFS) setting affects the 1-V output.
3. To select a second sensitivity setting while in single-channel mode, press
A/B, and enter the appropriate EUFS on the channel B screen.
Tip:
A single channel is tracked on channel A, leaving channel B
available for monitoring emission with an alternate EUFS setting. You