Xylem Sentix F 900-3 - Manual (Page 5)

SenTix Storage
13 ba75844e02 04/2010
Calibration
and measurement:
General rules
z Avoid the carryover of any solution (sample or buffer solution) from one
measurement to the next by taking the following measures:
– Shortly rinse the calibration and sample beakers with the solution the
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 wa-
ter and then carefully dab it dry.
z To measure in aqueous solutions, it is recommended to immerse the elec-
trode in a vertical or slightly tilted position.
z Observe the correct depth of immersion and make sure the contact be-
tween the junction and test sample is thorough. The junction is in the area
of the bottom end of the shaft (see arrow).
Caution: Only the shaft part of the combination electrode may be im-
mersed!
z For measurements in aqueous solutions, 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.
Storage
During short
measuring breaks
Immerse the electrode in reference electrolyte (KCl 3 mol/L, Ag
+
free). Prior
to the next measurement, shortly rinse the electrode with the test sample or
deionized water.
Note
Do not scratch the pH membrane.
SenTix
®
940
SenTix
®
F 900