YOKOGAWA Exaxt450, Руководство пользователя

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IM 12D08N05-01E
5-4
<5. MENU STRUCTURE COMMISSIONING>
5.4 Calibration settings
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Air adjust limit
To avoid cable influences on the measurement, a “zero” calibration with a dry sensor may
be done. If a connection box (BA10) and extension cable (WF10) are being used, “zero”
calibration should be done including this connection equipment.
When using a 4-electrode sensor additional connections are required. Temporarily
Interconnect terminals 13 & 14 with each other and 15 & 16 with each other before making
the adjustment. This is necessary to eliminate the capacitive influence of the cables. The
links should be removed after this step is completed.
As the calibration is performed in air the resistivity is infinite (open connection). Higher
conductivity values than the air adjust limit indicate the cell is not in air or is still wet. To
prevent wrong air calibrations a limit must be given here.
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c.c. high limit
High limit of the cell constant expressed in % of nominal value. During calibration this value
is used to check if the calibrated cell constant remains within reasonable limits.
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c.c. low limit
Low limit of the cell constant expressed in % of nominal value. During calibration this value
is used to check if the calibrated cell constant remains within reasonable limits.
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Stabilization time
During calibration the stability of the measurement is constantly monitored. When the
value is within a bandwidth of 1% over a period of the stabilization time, the calibration is
considered stable and the calibration may be completed.
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Calibration Interval
A user defined interval in which a new calibration should take place. If the interval is
exceeded the instrument will give a warning or a fail (user definable in error configuration
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5.5 Concentration
Concentration has a direct relation with the conductivity value at reference temperature.
This relation is built in every matrix which are used for temperature compensation. These
can be found in:
Commissioning >> Measurement setup >> Temp. compensation >> Method
By selecting one of the matrices for temperature compensation directly gives the
concentration value on the main display. If another temperature compensation method is
chosen (NaCl or T.C.), the relation between the conductivity at reference temperature and
the concentration is obtained from the “Concentration table”.
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Additional table
This 21x2 user defined concentration table is used to come to more accurate concentration
values compared to the temperature compensation matrix. Enabling this additional table
overrules the concentration values obtained from the matrix (if used).
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Unit for table
The way the concentration values are presented to the user. Changing the unit will not
result in a re-calculation of the table.