Suntex CT-6110-POL, Operation Manual

Page: 58 / 80

8.3.2 Span calibration
There are two ways of span calibration: The first one is to take some sample from the sample port
of pipe line and apply DPD method to measure the sample. Then, start the span calibration process
when the measurement value of the instrument is stable. Apply the DPD method value to adjust
the span calibration value until they are the same; the other way is to apply known residual
chlorine concentration reference solution. Firstly, turn off the original inlet valve and turn on the
reference solution inlet valve to input the reference solution into flow-through chamber. Wait until
the measurement value is stable and then start the span calibration. During the span calibration,
input the known concentration value.
Then, select to start electrode’s relative slope initialization or not. If yes, the slope will base the
circumstance and set as 100% relative slope; if not, the slope will be determined base on the
relationship which current circumstance slope divided theory basis slope. Hence, make slope
initialization at the first calibration work of the sensor in order to make a judgment standard of
future electrode aging or damaged. For example, when calibrated slope (%) has difference from
the slope of the 100% too much, it means that the electrode has been aging or damaged
phenomenon.
Note: The concentration of sample for span adjustment is highly suggested
greater than 0.2mg/l. (The span adjustment range has lower limit of 0.03mg/l.)
The process of span calibration work is as follows.
Press to confirm it.
Press to confirm it.
Press to confirm it.
Press or
to select span
calibration
Shows span current
value. Press
to directly finish the
reading, or wait
until the instrument
show the final
result.
Automatically shows
the span calibration
value. Press or
until the value is the
same with DPD
method value.
Press or
to activate slope
initialization or not.
Select NO for
regular work. Select
YES for first time
calibration work.
Press to finish
the calibration and
display the results.
54