Waters 2475, Operator'S Manual, Page: 91 / 228

Preparing to start a run 3-19
page 3-21 describe the functions, fields, screen number, display units,
allowable ranges, and default settings for the home screen and its secondary
function screens.
Accessing primary and secondary functions
You can access the primary and secondary functions from the home screen or
by pressing Next.
• Excitation Wavelength – Defines the operating excitation (x λ )
wavelength for the channel.
• Emission Wavelength – Defines the operating emission (e
λ
) wavelength
for the channel.
• EUFS (emission/sample energy units full scale) – Defines the
relationship between the fluorescence signal response (EU) and the
analog output voltage. The output voltage reaches full scale when
fluorescence attains the EUFS value.
• Gain – This setting controls the full-scale sensitivity of the detector by
defining the PMT gain factor from 1 to 1000. Each gain setting must
have a linear relationship with the actual fluorescence signal.
• Filter type – Defines your choice of noise filter (Hamming filter is the
default).
• Data units – Defines data units.
• Emission – The standard chromatography mode of the detector, which
normalizes the output to a water standard in emission units. Emission
units are measurements of light that are independent of PMT gain.
Through normal use, the optics in any detector age and, therefore,
change, resulting in measurement variation over time. By using
emission units, you can eliminate optics deterioration as a variable in
your measurements. When emission units are used, measurements
taken on different 2475 detectors are fully compatible with one another.
• Energy – Energy units do not have the normalization advantage. Those
traditional units of measurement conform to currently established test
methods. However, the results depend greatly on PMT gain.
Caution:
Changing the sensitivity (EUFS) setting affects only the
1-V output. The digital output at the RS-232 connector remains
unchanged.