Knauer WellChrom K-2600, Руководство пользователя

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28 Simple Maintenance
Simple Maintenance
Control of the lamp´s functionality
The deuterium lamp used with the photometer K–2600 has an extended
life time to ensure long-time functionality and reliable measurements
with low noise and baseline drift as well as high sensitivity. The actual
using time of the lamp depends on different factors, like the number of
lamp starts, the average burning time and your requirements
concerning noise and sensitivity.
To check the functionality of the lamp, the two intensity values
sig
and
ref
to be found in the menu Signal in the SETUP menu „SIGNAL“ on
page 12 provide helpful information. The ref value refers to the intensity
of the light measured in the reference channel and can be used for
checking the quality of the lamp.
We recommend to check the ref value at regular intervals under the
conditions mentioned above (dummy cell,
λ = 240 nm). This applies
especially in case higher noise levels or decreased sensitivity are
observed on working with the photometer K–2600. If these observations
coincide with a
ref
value of approx. 0.1 or less, a new deuterium lamp
should be installed, see SOP "Changing the lamp".
Changing the lamp
Remove the power plug before opening. Please let the lamp cool
down for at least 15 minutes after switching it off.
SOP 5 Changing the lamp
1. Unscrew the housing and remove it by lifting.
2. The lamp is located in a black housing on the right side
approximately in the middle of the instrument.
3. Pull the plug of the old lamp, located to the right in the front of the
instrument. Unscrew the two screws in the lamp socket with a
screw driver and remove the whole lamp from the instrument
including its cables.
4. Insert the new lamp assuring that it is correctly seated in the
guiding slot and screw it in securely.
Do not touch the glass of the lamp. Should you touch it acciden-
tally, clean it thoroughfully with a lint free cloth and i-Propanol.
5. Insert the plug of the lamp. The deuterium lamp has a 3-pole
plug, the halogen lamp a 2-pole one. Such it is impossible to plug
a lamp into a wrong socket.
6. If needed, adjust the lamp type in the SETUP menu, window
LAMP. In this window it is also possible to reset the working
hours of the lamp as described in „LAMP“ on page 11.
7. Put the lid back on from the top of the instrument and fasten the
screws of the cover.
Cleaning the flow cell
Noisy baselines and low sensitivities may be due to a dirty flow cell.
This may also be indicated by a low value for
sig
in the signal menu
when flushing the cell with pure solvent. All flow cells can easily be
disassembled for cleaning the lenses.