GMH3630E.08
H36.0.02.6C-08 page 5 of 10
r.H.
Td
T2
Td
m/s
kJ/kg
AL
Logg
T1
Corr
CAL
∆
Using the interface converter GRS3105 it is possible to connect several devices to a single interface. As a precondition the
base addresses of all devices must not be identical. In case several devices will be connected via one interface make sure to
configurate the base addresses accordingly.
'Address': Selection of Base Address
01, 11, 21, ..., 91
:
Base address for interface comunication.
Channel 1 will be addressed by the base address set, channels 2
and 3 will have the following addresses.
(Example: base address 21 - channel 1 = 21, channel 2 = 22, channel 3 = 23)
2
5
max
min
Electrode Maintenance
If it can no longer be calibrated, electrode needs maintenance.
Attention! The electrolyte is a corroding agent.
To maintain electrode please proceed as follows:
1. Unscrew diaphragm head and wipe clean of electrolyte solution using a paper cloth. Do not touch electrolyte. If your skin
has come into contact with electrolyte, rinse thoroughly with clear water.
2. Clean silver cathode with sanding paper (grain size 240). Do not polish silver cathode, surface should stay rough.
Remove all dust.
3. Remove filling screw and top up lost electrolyte (e.g. using disposable syringe))
4. Replace and tighten filling screw.
5. Top up diaphragm head with electrolyte avoiding air bubbles and place on table (cover table with absorbent paper first).
6. Keep electrode in a vertical position and replace diaphragm head on the electrode from the bottom. Electrolyte will be
forced out of the diaphragm head and spill over (put on disposable gloves or use paper towel to touch diaphragm head).
7. Wipe up excess electrolyte with paper cloth.
8. Check cathode for air bubbles.
If there are large air bubbles, remove diaphragm head again and repeat process as of point 5.
If O-ring has been damaged, it has to be replaced.
When maintenance has been completed replace protective flask. Re-connect electrode to measuring device and wait for at
least one hour till electrode can be calibrated.
Attention when working with electrolyte! The electrolyte is a corroding agent!
(strong caustic solution, KOH)
The Oxygen Electrode
Electrode design
The electrode housing is made of PVC. With the exception of the electrode shaft all parts need to
be maintained regularly and be replaced if necessary.
o Protective flask
: The protective flask is used to moisten the diaphragm. The service life of the
electrode will be prolonged. The protective flask contains water.
Attention! Use water only; never use calium chloride (KCI); this is only required for storage of
pH-electrode.
o Diaphragm head
: the diaphragm head is covered with a teflon diaphragm. It will be filled with
KOH electrolyte and screwed onto the electrode shaft (no air bubbles). Damages in the
diaphragm, large air bubbles or air bubble rings in the diaphragm head will result in erroneous
measurements. This may also be the reason for errors in the calibration. The diaphragm head
is a spare part and can be ordered individually.
o Filling hole
: If the electrode is used at high temperatures or if it has been stored without its
protective flask for a longer period of time, some electrolyte will be lost due to pervaporation.
During maintenance make it a rule to unscrew diaphragm head, remove locking screws and
top up electrolyte using a syringe. Replace and tighten locking screws.
The oxygen electrode is an active electrode consisting of a silver cathode and a lead anode with
the electrolyte being calium hydroxide (KOH). In case of oxygen being present it will be reduced at
the silver cathode, i.e. the electrode supplies a current. No oxygen means no current either. The
oxygen measurements use up both the silver cathode as well as the lead anode. The electrode is
subject to ageing. We, therefore, recommend to maintain the electrode at monthly intervals (p.r.t.
"Electrode maintenance').
Please note: Make it a rule to always store the electrode in a humid environment.
- in the storage flask filled with water
- in another container filled with water
If electrode has not been used for some time, clean diaphragm with soft cloth and remove
deposits, if any (algae, bacteria etc.).
Electrode shank
Filling hole
O-ring
Diaphragm head
