Waters 2489, Operator'S Manual

Page: 26 / 234

1-10 Theory and Principles of Operation
Requirement: Always ensure that the cuvette is removed and the cuvette
holder and front left panel door are secured during startup verification.
You can initiate a manual wavelength calibration at any time. A manual
calibration replaces the previous calibration data with new data. See
“Wavelength calibration” on page 3-30 for the manual wavelength calibration
procedure.
The verification and calibration algorithms are virtually identical. However,
the verification algorithm may issue an error message indicating that actual
data does not match stored data, where the calibration algorithm replaces the
stored data with the new data.
The detector wavelength verification procedures establish an approximate
Home position using a grating homing sensor. Once Home is established, the
detector locates and references the 656.1-nm peak in the deuterium lamp
emission spectrum.
The integral erbium filter moves into the common light path ahead of the flow
cell entrance slit, enabling the detector to locate three additional spectral
features at these wavelengths:
• 256.7 nm (UV)
• 379.0 nm
• 521.5 nm
The verification tests for the detector require 5 minutes of lamp warmup time
so the lamp can stabilize.
If you run the detector continuously, Waters recommends that you perform
wavelength verification weekly by turning off the detector, then turning it on
again.
See also: “Wavelength calibration” on page 3-30 .