eutech-instruments dissolved oxygen probe Manual De Usuario

 

 

 
All probe types need membrane replacement if the membrane is damaged. 
Probes used in aquaculture (type 1) may need renovation if, after some years use, 
it is not possible to calibrate up to the correct value. Other probes should NOT 
need renovation unless subject to extreme conditions. 

 
Tighten the cap 
firmly, but remember 
that you may have to  
loosen it yourself the 
next time the probe 
needs renovation! 
 
 
 
We do not 
recommend that a 
cap be re-used 
without replacing the 
membrane, as the 
membrane stretches 
to fit the cathode, and 
will not fit perfectly 
a second time. 

 
Eutech probes do NOT need regular renovation. 
 
1)  Start by cleaning the outer of the probe, then unscrew the cap. 
2)  TYPE 1 PROBES ONLY: inspect the anode. Clean off any loose white 

deposits with anon-metallic brush. If very corroded this type of anode can be 
replaced. Check that the nut under the anode is tight before fitting a new 
anode. 

3)  (All probes types) Rinse the probe inside.  
4)  Check the cathode and remove any deposits using a little wet or dry emery 

paper, grade 600. The cathode MUST NOT BE POBLISHED. 

5)  You can at this stage perform an easy check on the probe. Dry the probe- 

especially the cathode and are around it – completely, then observe the 
output signal – the probe should have zero output (less than 0.01 mV when 
measured at the probe). Contact your distributor if this is not the case. 

6)  The small vent hole in the top of the probe must be open, it can be cleaned 

with a needle. Insert the needle 12mm to clean the hole. 

7)  Fill a new (or renovated) cap to the brim with the electrolyte, and fit it to the 

upper part by holding the upper part, moving the cap up to the upper part 
and slowly screwing the cap into place without turning backs at any time. 
Excess electrolyte should dribble from the thread. 

 
After renovation the probe can be regarded as new. It should be hung up in air to 
stabilize for at least an hour before calibration. If possible re-calibrate after a day 
or two.  
 
A new membrane can be easily be fitted to the cap – see diagram. The membrane 
must be flat – if it wrinkles removes it and dry again with a new one. It is 
important at all parts are clean and dry. Neither O-ring nor membrane can be 
used more than once. 
 
This is normally only necessary after several years’ use, or if the membrane is 
damaged. Start by cleaning the outer of the probe. Then unscrew the cap and 
inspect the anode. Clean off any loose white deposits with a non-metallic bruch, 
e.g. a hard toothbrush. If the anode is very corroded replace it. Check that the nut 
under the anode is tight before fitting a new anode. Rinse the probe inside. Check 
the cathode and remove any deposits using a little wet or dry emery paper, grade 
600. THE CATHODE MUST NOT BE POLISHED. The small vent hole in the 
top of the probe must be open, it can be cleaned with a needle and rinsed. 
Replace the large o-ring with a new one. 
 
Fill new (or renovated) cap to the brim with electrolyte, and fit it to the  upper 
part by holding the upper  part with the vent hole away from you, moving the cap 
up to the upper part and slowly screwing the cap into place without turning 
backwards at any time. Ensure that the o-ring seats properly. Excess electrolyte 
should dribble out of the vent hole. 
 
After renovation the probe can be regarded as new. It should be hung up in air to 
stabilize for at least an hour before calibration. If possible, re-calibrate after a 
day or two. 
 

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