Agilent Technologies 8453 Operator's Manual page 190

Table 42
Diagnostics and Troubleshooting
General Troubleshooting Hints
Measurement Results Indicate Excessive Noise Over The Whole
Spectral Range
Ensure that the lamps are turned on when making measurements.
Measurements taken with both lamps off exhibit excessive noise over the
whole wavelength range. In addition, the self test (only Agilent ChemStation
software), lamp intensity, and stability diagnostics within the software can
aid in diagnosing problems within the optical system which contribute to
excessive noise. Causes and solutions for excessive noise over the whole
wavelength range are shown in Table 42.
Excessive Noise Over Whole Wavelength Range
Possible Causes
Light path is blocked.
Cuvette or flow cell not installed correctly.
Air bubble sticking on the quartz window of
the flow cell.
Source lens or spectrograph lenses dirty or
fogged.
Shutter not functioning or partly blocking
light.
Spectrophotometer data acqusition (SDA)
board may be defective.
Spectrophotometer lamp supply (SLS) board
may be defective.
Main power supply (MPS) may be defective. Exchange MPS.
Spectrograph electronics may be defective.
84
Action
Ensure that the light path is free and clear of
all obstructions
Check and correct cell installation.
Use cell cleaning fluid to passivate flow cell.
Clean lenses.
Exchange shutter assembly.
Exchange SDA board.
Exchange SLS board.
Exchange the optical unit.