Calibration Of Zero Point And Gradient - ProMinent DULCOMETER D1Cb Series Instructions For Assembly And Use

Measured Variables and Operating Menus for Amperometric Sensors
Necessity of calibrating the zero point
Calibration of the zero point is not generally
necessary. Calibration of the zero point is
only necessary if the sensor is operated at
the lower limit of the measuring range or if
the 0.5 ppm sensor version is used.
During calibration, the DULCOMETER
sets the actuating outputs to "0". The exception
to this is if a basic load or a manual actuating
variable has been set, this remains active. The
mA standard signal outputs are frozen. The
reading frozen at the start of calibration is
suggested as a DPD value. The DPD value can
be set using the arrow keys. Calibration is only
possible if the DPD value is ≥ 2 % of the meas‐
uring range of the sensor.
6.6.2 Calibration of Zero Point and
Gradient
NOTICE!
Prerequisites for correct calibration of the
sensor gradient
–
The DPD method required by the
metering medium employed will be
used
–
The run-in time for the sensor has been
adhered to
–
There is permitted and constant flow at
the flow gauge
–
There is temperature equalisation
between the sensor and the sample
water
–
There is a constant pH value in the
permitted range
58
Calibration of amperometric sensors: gradient (in
the reduced and complete operating menu)
The sensor is fitted, flushed with sample water
and connected electrically to the
DULCOMETER
There has to be adequate metering medium in
the sample water for calibration (> 2% of the
measuring range of the sensor).
Remove sample water directly at the measuring
® D1Cb
point and determine the content of metering
medium in the sample water in "ppm" using an
appropriate reference method (e.g. DPD, titra‐
tion etc.) Enter this value as follows into the
DULCOMETER
1.
Select Calibration menu. Then press
ð
2. Take a sample of water and perform a
reference measurement within 15
minutes.
3. Select "DPD value" of unit to be calibrated
using the
4.
Continue with
5. If necessary adjust the flashing ppm
value using keys
value determined by the measurement
ð
6.
Then press the following key twice
ð
D1Cb and run in.
®
® D1Cb :
The current reading will now be
frozen.
key
, and
The mA value of the sensor shown
in this display now corresponds to
the reading in "ppm"
The display now shows the value
determined for the zero point and
gradient. Refer to the Error Message
table should an error be displayed
Ä Table on page 56
to the