00108103w REV 0421 6 of 10
5. Place new battery pack in battery cover and
resecure to base.
6. To reconnect battery pack wire to circuit board,
line up the connector of the battery pack so that
the protruding ledge faces the tab (locking guide)
on the circuit board. Push the connector straight
down over the pins on the board. Do not force the
connector; if aligned properly, it should click into
place with little effort.
7. Reassemble the instrument cover and base.
8. Charge the new battery for at least 12 hours.
9. Dispose of old battery in accordance with local
regulations.
Electrode Storage
• Short-term storage (overnight): Immerse
the electrode tip in electrolyte solution. Keep the
electrode cable plugged into the electrode port on
the meter so that the system is internally short-
circuited and electrode symmetry (equilibration)
is maintained.
• Long-term storage: Rinse the electrode with
Milli-Q
®
water or equivalent and store dry and
in the dark. Do not allow electrode to dry without
first rinsing with Milli-Q
®
water to remove salts
and proteins.
Electrode Cleaning
With repeated use, the electrode surface can become
coated with protein or other foreign materials. This
build-up can degrade the performance of the system.
After every use, rinse the electrodes with Milli-Q
®
water and store them as indicated above. Periodically
clean the electrodes with Tergazyme
®
detergent
(Alconox, Inc.
®
cat. no. 1304) as follows:
1. Rinse the electrodes with Milli-Q
®
water
and dry them.
2. Make a 1% solution of Tergazyme
®
detergent
and suspend the electrode tips in the solution
with the exposed electrode surfaces fully immersed.
If desired, brush the electrode surfaces with a
soft brush (e.g., tooth brush).
If the electrode is...
Then soak it in solution for...
not cleaned routinely 12 hours
is on a weekly
cleaning schedule
30–60 minutes
is cleaned daily 5 minutes
3. Rinse well with Milli-Q
®
water. Store as detailed in
Electrode Storage section.
Sanding (only when measuring voltage)
4. Lightly rub the voltage electrodes (the two silver
pellets on the inner surfaces near the electrode tips)
with 600-grade ultrafine sandpaper (provided) or
an ink eraser. Do not sand the silver pellets on the
outside of the electrode tips.
CAUTION: Only a very thin surface layer of the
pellet should be removed. Repeated rubbing will
eventually remove the Ag/AgCl pellet. When rubbing
no longer improves the voltage readings, the
electrode should be replaced.
Troubleshooting
Most of the time, system problems are related to the
electrode rather than the meter itself. However, if the
meter does fail, it is most often due to switch failure
caused by corrosion from accidental spillage of saline
solution or culture media on the meter. If functional
testing indicates acceptable performance, and the
meter has not been exposed to salt solutions, then
the meter is working correctly.
When the electrode fails, the most common symptom
is an unstable or unusually high reading. The following
qualitative method may be helpful in determining
whether or not the electrode is functional:
• Check the resistance of a well filled with electrolyte
and across a blank culture insert filled with
electrolyte. The resistance of electrolyte alone
should be less than 50 Ω and stable if the electrode
is kept stationary. The resistance of the blank insert
is normally in the 80 to 200 Ω range, depending
on the brand and size.
• When the meter displays a lower than expected
resistance, but is stable and reproducible, the most
likely cause is the cell culture, not the electrode
or the meter.
• During normal use, it may helpful to write down
the resistance range of each particular type of blank
insert with the specific culture media used. If the
electrode is subsequently suspected of having a
problem, a comparison of current readings with past
readings on the same blank insert and culture media
may assist in determining if the electrode
is functioning properly.
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