Maintenance
60
6.
Display is automatically returned to the zero calibration mode.
7.
Hold down ESC to return to the meas mode.
When automatic zero calibration function (option) is provided
Manual zero calibration
When zero calibration is specified manually, the electric ball valve for the sample water line
will be closed in a few seconds and the solenoid valve for zero water will be opened. When
you press ENT after the indication has been stabilized, the zero calibration will be completed.
Once the zero calibration is completed, the valve will return to its original condition.
Automatic zero calibration (option)
Call up “A.CAL” in the cal mode and press ENT. While zero water is being run automatically,
the system will perform zero calibration when it judges that the measured value has been
stabilized.
Even if the turbidity of zero water is high, zero calibration may be performed as long as the
automatic zero calibration conditions are met. In order to avoid this, it is necessary to set
stricter criteria. To make the criteria stricter, decrease the stability level or lengthen the stability
time in the setup menu. However, if the criteria are too strict, zero calibration may not be
completed within the specified time, and an error may also occur. Adjust the stability level and
time so that the system can make the optimum judgment for zero calibration.
By setting the cycle for the automatic zero calibration, zero calibration can automatically be
performed at the specified interval.
Tip
In the zero calibration mode, a negative measured value is also displayed.
Checking the zero calibration data
On the calibration data check screen, checks can be made of the amount of transmitted light
during zero calibration and the number of days elapsed since the last zero calibration. A check
of the amount of transmitted light makes a comparison with the initial amount of transmitted
light. It is assumed that fluctuations in the amount of light are attributable to the deterioration
of light sources, the influence of temperature, or contamination on the cell. The default value is
the factory-configured amount of transmitted light. The default value is updated each time
zero calibration is performed.
Procedure for checking the calibration data
1.
Display the calibration data check screen on the converter.
Press
/
in the meas mode to display “CAL.dAt”.
Hold down
4 times
