Manual PRO v.3
75 / 78
measuring zone of the sensor that there is no air remaining in the
measuring zone.
The sensor has been a
number of hours measuring
the water without free
chlorine
Let water containing free chlorine
circulate through the sensor holders for
1 hour.
Reading below the
DPD-1 measurement
Insufficient flow in the sensor
holders
Adjust the flow reaching the sensor
holders. Clean the filter and the flow
regulator of the sensor holders.
There are air bubbles in the
measuring zone of the sensor
Bleed the sensor holders and ensure
that there is no air remaining in the
measuring zone.
Sensor passivated for
working at more than 3 mg/l
Clean the sensor by submerging it in
an HC10.1M solution for 20 seconds.
The pH of the water is higher
than at the time of calibration
Calibrate the sensor to the new pH
value.
The pH is above 9, and
therefore outside the
recommended reading zone,
Adjust the pH within the acceptable pH
range: 6.5-9
Reading above the
DPD-1
The sensor has been
calibrated without waiting for
sufficient conditioning time
Repeat conditioning of the sensor and
recalibrate.
