Hach-Lange NO3D sc Nitrate Sensor - Manual (Page 22)

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Operation
4.6 Calibration
The membranes on the ion-selective electrodes are not 100%
selective due to other substances that may affect the
measurement. Perform a matrix correction to compensate the
influences of other ions on the nitrate ISE electrode.
Chloride has the largest interference effect on the nitrate
membrane. This problem is compensated in the NO3D sc sensor
using the integrated chloride electrode.
CARTRICAL TM is a compact sensor cartridge with 3 electrodes,
which are perfectly factory calibrated to each other.
Cross sensitivities between nitrate and chloride are automatically
eliminated. Solids do not interfere with the measurement. Due to
matrix effects calibration and validation can not be performed with
standard solutions. A matrix correction can be carried out quickly
and easily at any time.
Important Note: Matrix correction must not be performed until the
sensor has been immersed in the process longer than 12 hours.
12 hours is the mimimum amount of time required for the ISE
membranes to adapt to the waste water matrix.
The 12 hours is required to allow the sensor cartridge to adapt to
the process.
4.6.1 Sensor code calibration
When activating a new sensor cartridge or during initial calibration,
the sensor code must be entered. The default sensor code is
IIIIIIIIIIIIIIII (all 16 I capital letters are the same). With this code, the
sensor is ready for operation. To meet published specifications,
enter the individual sensor code for the specific CARTRICAL
cartridge.
Enter the sensor cartridge's sensor code to accept the CARTRICAL
calibration. The sensor code is a 16 character code (letters and
numbers) and will be supplied with the sensor cartridge certificate.
The code contains the factory calibration for the sensor cartridge,
DIAG/TEST
PROBE INFO
Information on the connected sensor
EDIT NAME
Name of the connected sensor
SERIAL NUMBER Serial number of the connected sensor
SOFTWARE VERS Software version
CAL DATA Data of the selected MATRIX correction
SIGNALS
Signals and measurements of the individual measurement channels
NITRATE
Displays the signals and measurement results
CHLORIDE Displays the signals and measurement results
TEMP Displays the temperature
COUNTERS
Sensor code (time the sensor code was entered generally corresponds with the age of the
cartridge) and CAL. days
SERVICE Performing a sensor check using TEST CARTRIDGE (see 7.2 on page 37 )
4.5 Sensor setup menu (continued)