Hach-Lange NO3D sc Nitrate Sensor - Manual (Page 24)

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Operation
4.6.3 Matrix correction
Note: Perform laboratory values or comparative values with cuvette tests
timely or stabilized the sample, to avoide a modification of the sample
concentration.
In 7.3 Validation accessories on page 37 you can find
recommended tests which can be used for laboratory
measurements.
Note: Laboratory comparison or verification samples are time sensitive.
Perform analysis of these samples as quickly as possible to minimize the
potential for a bias or interference in the results.
4.6.3.1 MATX1 correction (one point matrix correction)
Proceed as follows to perform the MATX1:
1. Select SENSOR SETUP>NO3D SC>CALIBRATE> CAL CONFIG .
2. Select MATX1 in the selection window and press ENTER .
3. Select CONC MEAS 1 .
The currently measured nitrate and chloride values are displayed.
The drift indicates whether the measured value is stable.
4. Wait until the measured value is stable and confirm by pressing
ENTER (Drift should be < 0.03 mg/L). The values for nitrate and
chloride are saved.
5. Immediately after saving, take a water sample for laboratory
analysis from as close to the sensor as possible.
6. Analyze the sample immediately after taking the sample as its
nitrate content can change quickly.
After determining the laboratory reference value, proceed as
follows:
7. Select SENSOR SETUP>NO3D SC>CALIBRATE>
SET NO3–N CONC .
8. Enter the laboratory value (reference value) for NO
3
–N and
press ENTER to confirm. Confirmation of the entered laboratory
value activates the matrix correction.
4.6.3.2 MATX1 CL- correction
Proceed as follows to perform the MATX1 CL-:
1. Select SENSOR SETUP>NO3D SC>CALIBRATE> CAL CONFIG .
2. Select MATX1 CL- in the selection window and press ENTER .
3. Select CONC MEAS 1 .
CALIBRATE
CAL. CONFIG.
DATE
CONC MEAS 1
SET NO3–N CONC
READING STABLE?
NO3–N:
DRIFT
CL-
DRIFT
CALIBRATE
CAL. CONFIG.
DATE
CONC MEAS 1
SET CL- CONC
SET NO3–N CONC