Waters 2489, Руководство оператора

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Using the operator interface 3-15
Analog out
(dual
λ
)
In addition to the selections for single l above, you can
chart the same parameters on the other channel at a
different wavelength, and you can chart the following
parameters:
• MaxPlot – Charts the absorbance of multiple
compounds with different absorbances at two
different wavelengths on a single data channel.
Scaling for MaxPlot is the same as for Absorbance
above, except that the charted absorbance is the
larger of the two absorbances measured on the
wavelengths on channel A and channel B. The
detector uses the AUFS, absorbance offset, and
voltage offset of the selected channel regardless of
which absorbance (channel A or channel B) is
larger.
Volts out = Larger absorbance (A or B) × 2 V/AUFS
(of selected channel)
• RatioPlot (A/B) – Charts the ratio of absorbances
at two wavelengths. Theoretically, the ratio is
constant for a pure chromatographic peak and
variable for an impure peak. This mode uses the
three ratio parameters on screen 5 of 5 (see the
figure below).
– Minimum AU: This setting defines the minimum
AU value for either wavelength (A or B) before the
actual ratio is calculated. Both absorbance values
(A and B) must be above this value or 0 V is
charted. If both absorbances are above this value,
the absorbances are divided (A/B) and charted. The
output voltage is scaled proportionally to the ratio
depending on the selected channel minimum ratio
and maximum ratio settings.
– Minimum ratio: An actual ratio equal to the
minimum ratio value results in 0 V being charted.
Detector functions
Function Description