Xylem WTW SenTix HW-T 900, Operating Manual

Page: 7 / 14

SenTix
®
HW-T 900(-P) Storage
7
ba77090e03 06/2021
beakers are to be filled with next.
– Between measurements, rinse the electrode with the solution that fol-
lows. Alternatively, you can also rinse the electrode with deionized
water and then carefully dab it dry.
 Immerse the electrode in the solution in a vertical or slightly tilted position.

Make sure the immersion depth is correct. The ground junction must be
completely submersed in the solution. At the same time, the level of the
reference electrolyte must be at least 2 cm above the level of the solution.
 Provide approximately the same stirring conditions for measuring as for
calibrating.
Subsequent
calibrations
The frequency of subsequent calibrations depends on the application. Many
meters provide an option where you can enter a calibration interval. After the
calibration interval has expired, the meter will automatically remind you of the
due calibration.
3 Storage
During short
measuring breaks
With the refilling opening open, immerse the electrode in reference
electrolyte (KCl 3 mol/L, Ag
+
free). Observe the minimum depth of
immersion. Prior to the next measurement, shortly rinse the electrode with
the test sample or deionized water.
Overnight or
longer
Put the clean electrode in the watering cap that is filled with reference
electrolyte (KCl 3 mol/L, Ag
+
free) and close the refilling opening.
NOTE
pH electrodes must not be stored dry or in deionized water. The elec-
trode could be permanently damaged by this. If the liquid in the
watering cap has dried up, condition the electrode in reference electro-
lyte (KCl 3 mol/L, Ag+ + free) for at least 24 hours.
Prevent contact of the pH membrane to the beaker bottom to
avoid scratches on the pH membrane.
During longer storing periods, salt sediments may develop on the
watering cap and the refilling opening. The salt sediments do not
affect the measuring characteristics.
 Remove any salt sediments with deionized water.
 Refill the reference electrolyte solution when the filling level is
low (see chapter section 5 M
AINTENANCE AND CLEANING
).