Meter Maintenance; Electrode Maintenance; Error Messages - Mettler Toledo SevenGo Duo pro pH/ORP/Ion/Conductivity meter SG78 Mode D'emploi

Maintenance
8 Maintenance

8.1 Meter maintenance

Never unscrew the two halves of the housing!
The meters do not require any maintenance other than an occasional wipe with a damp cloth and the
replace ment of dead batteries. The housing is made of acrylonitrile butadiene styrene/polycarbonate
(ABS/PC). This material is sensitive to some organic solvents, such as toluene, xylene and methyl ethyl
ketone (MEK).
Any spillage should be wiped off immediately.

8.2 Electrode maintenance

Make sure the pH electrode is always kept filled with the appropriate filling solution.
For maximum accuracy, any filling solution that may have "crept" and encrusted the outside of the elec-
trode should be removed with deionized water.
Always store the electrode according to the manufacturer's instructions and do not allow it to dry out.
If the electrode slope falls rapidly, or if the response becomes sluggish, the following procedures may
help. Try one of the following, depending on your sample.
Problem
Fat or oil build-up
pH sensor membrane has dried out
Protein build-up in the diaphragm of a pH sensor
Silver sulfide contamination of pH sensor
Note
Cleaning and filling solutions should be handled with the same care as that given to toxic or corrosive
sub stances.
8.3 Disposal

8.4 Error messages

Message
pH/mV/ion/tem per a ture/con duc tiv i-
ty/TDS/salin i ty/resis tiv i ty exceeds max.
lim it
30
Run a new calibration after treatment.
In compliance with European Directive 2002/96/EC on Waste Electrical and Elec-
tron ic Equipment (WEEE), this device must not be disposed of together with
domes tic waste. The same principle applies to countries outside the EU, in accor-
dance with their national regulations.
Please dispose of this product in accordance with local regulations, in a separate
col lec tion point for electrical and electronic devices.
In cases of doubt, please contact your local authority or the dealer from whom you
pur chased the device.
If this device is passed on to a third party (e.g. for further use in a private or com-
mer cial/indus tri al context), the general principle of this regulation must be com mu-
ni cat ed at the same time.
Thank you for your contribution towards environmental protection.
Description and Resolution
Measurement limits are activated in the menu settings and
mea sured value is outside these limits.
●
Action
Degrease the membrane with cotton wool soaked
in either acetone or a soap solution.
Soak the tip of the electrode overnight in 0.1M HCl
Remove deposits by soaking the electrode in an
HCl/pepsin solution.
Remove deposits by soaking electrode in a thio-
urea solution.
Check the sample.
pH/ORP/Ion/Conductivity meter SG78