Xylem handylab multi 12 - Manual (Page 39)

handylab multi 12 Operation
39 ba75371e03 11/2009
4.4.5 Determining the cell constant (Calibration in the
control standard)
Why determine the
cell constant?
Aging slightly changes the cell constant, e. g. by coatings. As a result, an in-
exact measured value is displayed. The original characteristics of the cell can
often be restored by cleaning the cell. Calibration determines the current val-
ue of the cell constant and stores this value in the instrument.
Thus, you should calibrate at regular intervals.
In the delivery condition, the cell constant of the measuring instruments is set
to 0.475 cm
-1
.
AutoRead The calibration procedure automatically activates the AutoRead function.
The AR display indicator flashes. The calibration process is finished when AR
stops flashing.
Displaying the
calibration data
You can view the data of the last calibration on the display. The proceeding
is described on page 50.
Printing the
calibration
protocol
The calibration record contains the calibration data of the current calibration.
You can transmit the calibration protocol to a printer via the serial interface
(see page 52).
Note
You can automatically print a calibration record after the calibration. To do so,
connect a printer to the interface according to section 4.7.2 before calibrating.
After a valid calibration, the record is printed.
Sample printout:
CALIBRATION PROTOCOL
14.04.01 11:37
Device No.: 99990000
Calibration Conductivity
Cal time: 14.04.01 / 11:37
Cal interval: 180d
Cal Std.: 0.01 mol/l KCL
40.0 °C
Conduct./Tref25: 1413µS/cm
Cell Const : 0.478 1/cm
Probe : +++