Xylem WTW SenTix 950, Operating Manual

Page: 8 / 14

Maintenance and cleaning SenTix
®
950 / 980 / Micro 900(-P)
8
ba75843e04 06/2017
5 Maintenance and cleaning
Refilling the
reference
electrolyte
During operation, a small amount of reference electrolyte leaks through the
junction from the electrode into the test sample. If the level of reference elec-
trolyte becomes too low with time, refill it through the refilling opening. Refill-
ing is very easy with the enclosed dropping bottle. Proceed as follows:

Cut off the tip of the dropping bottle at a right angle until the opening in the
tip can be seen

Open the refilling opening of the electrode
 Press the tip of the dropping bottle into the refilling opening while turning
it slightly
 Pump the reference electrolyte in the shaft using the dropping bottle

Pull the dropping bottle out of the refilling opening while turning it slightly
as necessary.
Cleaning Remove water-soluble contamination by rinsing with deionized water.
Remove other contamination as follows:
NOTE
Hydrofluoric acid, hot phosphoric acid and strong alkaline solutions
destroy the glass membrane.
Contamination Cleaning procedure
Fat and oil Rinse with water containing household wash-
ing-up liquid
Lime and hydroxide deposits Rinse with citric acid (10 % by weight)
Proteins Immerse in pepsin cleaning solution PEP/pH
for approx. 1 hour.
Note: Make sure the level of the reference
electrolyte is above that of the cleaning solu-
tion.