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inoLab 740
Why calibrate?
When to calibrate?
Calibration procedures
AutoRead
Calibration record
ba75446e05
07/2010
8.2
Calibrating for D. O. measurements
D. O. probes age. This changes the slope of the D. O. probe. As a
result, an inexact measured value is displayed. Calibration determines
the current slope of the probe and stores this value in the instrument.
After calibrating the D. O. probe in the air calibration vessel, the
measuring system displays a value of approx. 102% oxygen saturation.
If the value of the oxygen saturation obtained by checking the probe in
the air calibration vessel is different from this, it is necessary to calibrate
or clean the probe.
If possible, check the probe signal in the air calibration vessel before
each series of measurements.
At regular intervals (14 days)
After connecting another D. O. probe
The following calibration procedures are provided:
Calibration in water vapor-saturated air.
To calibrate the CellOx 325, use the OxiCal
sel (accessory), to calibrate the DurOx 325, use the OxiCal
calibration vessel (contained in the scope of delivery of the sensor).
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.
The calibration procedure automatically activates the AutoRead
h
function. The
display indicator flashes. The calibration process is
h
finished when
stops flashing.
The calibration record contains the calibration data of the current
calibration. You can call up the calibration record by outputting the data
storage (section 11.3).
Note
You can automatically print a calibration record after the calibration. To
do so, switch on the printer before calibrating (print LED lights up
green). After a valid calibration, the record is printed.
Sample printout:
Calibration O2
Cal Date: 05.12.1999
Cal Time: 22:46
Cal Interval: 14 days
OxiCal
Rel. slope 0.73
Sensor +++
User: xxxxx
* for the inoLab Oxi 740 and BSB/BOD 740 measuring modules
Dissolved oxygen (D. O.)
®
-SL air calibration ves-
®
-D air
123
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