eDAQ Picostat, User Manual

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Chapter 3 — The Picostat 39
Maintenance
Your Picostat will not require maintenance during daily operation.
However, you should periodically check the Picostat for optimum
results.
First set up the Picostat and e-corder as outlined earlier in this Chapter.
Disconnect the electrode cable from the Picostat. Open the Picostat
Control window,
Figure 3–7 or Figure 3–8 . Adjust the current range to
10 pA, the Low Pass filter to 10 Hz, and select Real mode. After a
couple of seconds the resulting current signal should have stabilised
and be close to zero. If the current signal is drifting significantly, or is
greater than ±5 pA, then contact your eDAQ representative — it is
possible that stray static discharge may have damaged the Picostat’s
electrometer chip.
Also periodically repeat this procedure with the electrode cable
connected, and attached to the 100 MΩ test resistor, as described in
the section on
First Use, page 33 . If the current signal does not obey
Ohm’s law, then first recheck your connections of the Picostat to the
e-corder , page 31 . If the problem persists then it is possible that the
electrode leads or the Picostat itself has become damaged.
If these tests indicate that the Picostat is working correctly, but you are
still experiencing difficulties with your experiments, then you should
now check the electrodes you are using, the connections to them, and
the design and condition of the reaction vessel, and any salt bridges
that you are using.