Oxygen Calibration - wtw Multi 340i Operating Manual

Multi 340i
Calibration proce-
dures
Sensor evaluation
O
C A L
1
7 6
°
Cal
O
S
0 8 8
1 7 6
Cal

Oxygen calibration

The calibration is performed in water vapor-saturated air. Use the
®
OxiCal -SL air calibration vessel (accessories) for the calibration.
After the calibration, the measuring instrument evaluates the current status
of the sensor against the relative slope. The evaluation appears on the dis-
play. The relative slope has no effect on the measuring accuracy. Low values
indicate that the electrolyte will soon be depleted and the probe will have to
be regenerated.
Display
E3
Invalid calibration
Oxygen calibration procedure:
l Keep the OxiCal
l Connect the D. O. probe to the measuring instrument.
If necessary, press the <M> key repeatedly until the status display O
(oxygen measurement) appears.
l Put the D. O. probe into the air calibration vessel.
l Press the <CAL> key repeatedly until the oxygen calibration mode ap-
pears (display O
C
TP
l Press <RUN/ENTER>. The AutoRead measurement begins.
l When the measured value is stable, the instrument displays the value of
the relative slope and the sensor evaluation.
l Switch to the measuring mode with <M>.
° C
TP
AR
Relative slope
S = 0.8 ... 1.25
S = 0.7 ... 0.8
S < 0.6 or S > 1.25
®
-SL air calibration vessel ready.
CAL).
2
Oxygen calibration
S = 0.6 ... 0.7
2
9