Yokogawa 2-Wire Dual Channel Transmitter/Analyzer FLXA21 - Manual (Page 97)

<7. COMMISSIONING OF SC (Conductivity)>
7-5
IM 12A01A02-01E 5th Edition : Oct. 31, 2013-00
NOTE
The temperature compensation is not performed around zero. In this case, a warning may be
issued.
7.1.5 Calibration settings
The screen flow differs depending on the combination of objects to be measured.
l Air adjust limit
Generally, air calibration is not required. To avoid the effects of the cable on the measurement of
lower conductivities such as pure water, a “zero” calibration with a dry sensor may be done.
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 that the cell is not in air or is still wet. To
prevent wrong air calibrations, a limit must be given here.
l c.c. high
High limit of the cell constant expressed as a % of the nominal value. During calibration this value
is used to check if the calibrated cell constant remains within reasonable limits.
l c.c. low
Low limit of the cell constant expressed as a % of the nominal value. During calibration this value
is used to check if the calibrated cell constant remains within reasonable limits.
l Step Range
Set the range over which the stability of a measured value is checked. If variations of a measured
value over the stabilization time are within this set value, the measured value is judged to have
stabilized.
l Stabilization time
During calibration, the stability of the measurement is constantly monitored. When variations of
the value are within a value set in Step Range over this stabilization time set here, the value is
regarded as being stable. If the value does not stabilize within 10 minutes, calibration is aborted.
l Calibration interval
Set the interval in which a new calibration must take place. If the interval set here is exceeded,
the instrument will be notified according to the setting in “Calib. time exceeded” in the error
configuration.
7.1.6 Concentration
The “Concentration” can be set only when “Conduct. + Concentr.” or “Concentration” is selected
for the Measurement in the Measurement setup menu.
The corresponding concentration given by a measured conductivity can be shown on the Main
display or the Home display.
SC
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