Evoqua WALLACE & TIERNAN SFC, Original Instruction Manual

Page: 205 / 288

SFC
Operation
6.
205
6.4.3 Membrane sensors calibration
Calibration is nearly identical for all membrane sensors. The
difference lies in the fact that some of the chemicals are measured
manually with a photometer and others with a colour meter.
A 1-point calibration is available to calibrate the total chlorine
measurement and the combined chlorine measurement.
Either the total chlorine or the combined chlorine must be
calibrated.
For the selective ozone, chlorine dioxide and free chlorine
measurements, 1-point or 2-point can be selected in the
calibration menu of the „Calibration mode“.
2-point calibration provides the option to compensate for possible
measuring cell zero point offsets.
Total chlorine
In the calibration of the total chlorine measurement, the free
chlorine value is also essential. For this reason, prior to calibration,
the current free chlorine value must be entered in the menu
calibration-Cl-total "Enter free Cl2". Only then shall the total
chlorine calibration be carried out as follows:
1 Using the soft key "calib", select the menu item "Cl-total" and
press "Enter" to confirm.
2 Select the parameter "calib. total" and press "Enter" to confirm.
3 Open the input menu by pressing "Enter". The actual
measured sensor value is thereby cached and can be used for
later calibration. This is essential for fluctuating measurement
values.
4 Immediately after this extract specimen of sample water and
determine the total chlorine content using a comparative
device.
5 Use the arrow keys to enter the determined value.
6 Save the value by pressing "ENTER".
Combined chlorine (optional)
The calibration of the combined chlorine measurement also takes
into account the free chlorine value. It must therefore be ensured
that the free chlorine value (from external measurement system) is
correctly calibrated. Calibration can then take place as follows:
1 Using the soft key "calib", select the menu item "Cl-comb" and
press "Enter" to confirm.
2 Select the parameters "calib. comb" or "calib total" and press
"Enter" to confirm. It does not matter which value is entered.
3 Open the input menu by pressing "Enter". The actual
measured sensor value is thereby cached and can be used for
later calibration. This is essential with fluctuating
measurement values.