wtw Oxi 3310, Operating Manual

Page: 30 / 62

Operation Oxi 3310
30 ba75804e06 03/2012
4.4.4 D.O. calibration
Why calibrate? D.O. sensors age. This changes the slope of the D.O. sensor.
Calibration determines the current slope of the sensor and stores this
value in the instrument.
When to calibrate?

After connecting another D.O. sensor

When the sensor symbol flashes (after the calibration interval has
expired).
Calibration datasets The Oxi 3310 administrates two sets of calibration data:
Sensors of different types can be calibrated separately from each other.
When one sensor type is calibrated, the calibration data of the other
type remains stored. The Oxi 3310 recognizes the type of the
connected sensor and automatically uses the correct calibration data.
Calibration procedures With the Oxi 3310, 2 calibration procedures are available:

Calibration in water vapor-saturated air.
Use an OxiCal
®
air calibration vessel for calibration.

Calibration via a comparison measurement (e.g. Winkler titration
according to DIN EN 25813 or ISO 5813). At the same time, the
relative slope is adapted to the comparison measurement by a
correction factor. When the correction factor is active, the [Factor]
indicator appears in the measuring window.
Stability control
(AutoRead)
In calibration, the Stability control function (AutoRead) is automatically
activated.
Display calibration data
and output to interface
You can have the data of the last calibration displayed (see section
4.4.5). Subsequently, you can transmit the displayed calibration data to
the interface, e. g. to a PC, with the <F2>[USB output] key.
Note
The calibration record is automatically transmitted to the interface after
calibrating.

Set 1 for the type, "CellOx": – CellOx 325

Set 2 for the type, "DurOx": – DurOx 325