Xylem YSI VARiON Plus 700 IQ H, Operating Manual, Page: 34 / 62

Matrix adjustment, check and calibration VARiON
® Plus
700 IQ H
34
ba76207e02 12/2020
Preparations and
instructions on how to
keep the basic
conditions
 Select a place where clean working conditions and a constant, suf-
ficiently high temperature are granted (a room, e.g. laboratory).
Temperatures under 10 °C extend the conditioning time consider-
ably.
 Make sure the temperature of all components (sensor, standard
solutions, containers, accessories etc.) is similar and constant. We
recommend to store the standard solutions in the same place where
the check or calibration is carried out.
 Use containers and accessories (beaker, stirring rod) that are abso-
lutely clean and without detergent residues. Detergent residues can
seriously affect the function of the electrodes.
 Remove the protective hood and clean the sensor thoroughly.
Before the check, rinse the sensor with standard solution VARiON
®
/
ES-2.
 Make sure the depth of immersion is sufficient (minimum 5 cm).
 Make sure there are no air bubbles in front of the electrode mem-
brane.
 Conditioning times: During the conditioning steps, all relevant elec-
trode voltages are indicated on the display. Thus you can observe
the conditioning process.
 Regular stirring accelerates the conditioning process considerably.
Stirring with a stirring rod or the sensor itself is sufficient.
 For calibration, the standard solution is discarded after conditioning.
This is pointed out by a corresponding note in the calibration routine.
It is essential for an exact calibration result.
 Use the Online help if you are unsure of anything during calibration.
4.3.2 Result of the check
Evaluation At the end of the check, the result for the electrodes is shown on the
display with "+" (successful) or "-" (unsuccessful). The exact check
criteria are given in the
Online help of the result display. At the same
time the result is entered in the log book as an info message. There is
no entry in the calibration history.
Sensor history The result of the check is available in the Sensor history (see section
4.4 S
ENSOR HISTORY
).
4.3.3 Result of the calibration
Evaluation With calibration, the system automatically evaluates the condition of an
electrode based on the data of its characteristic curve. The drift poten-
tial and slope are evaluated separately. For a calibration procedure to