EN - Page 6
3.
Checking the Mini-HydroFlex
If you want to check HydroFlex, we recommend the standard calomel electrode or, if
necessary, the silver silver chloride electrode.
We recommend the following solutions as measuring solution:
Hydrochlorid acid
pH 0
244 mV
Hydrochloric acid/citric acid
pH 2
362 mV
Citric acid /sodium chloride /sodium hydroxide solution
pH 4
480 mV
The potentials given refer to the standard calomel electrode at 25 °C.
4.
Maintenance
Replacement of the Hydrogen cell
Unscrew the black cap and remove the hydrogen cell.
In the recess in the electrode head you see a small O-ring.
Please grease this, e. g. with silicone grease.
Take the replacement hydrogen cell and remove the protective foil.
There are two openings visible. If any adhesive residue remains,
remove it by rubbing with a cloth.
Insert the hydrogen cell with these two openings down into the recess.
