Hach AN-ISE sc Addendum To The Operator Manual page 13

Enter value point
AN–ISE SC NH –N
4
AN–ISE SC K
Lab value NH –N
4
Confirm the entry.
4.3.4.3 2-point value correction
Calibration
Matrix correction
More corrections
Information
1Applies to AN-ISE sc
English
5. Go to the sensor menu and select
1-point value correction and confirm by
CORRECTION >
pressing .
ENTER
6. Select the parameter1 (NH
correction.
Note: The example opposite shows the NH
AN-ISE sc probe.
7. Enter the three values for the sought correction point and push
Confirm the entry. to activate the correction.
Correction result is shown.
Note: If a correction does not produce a successful result, calculations are
made with the previous correction.
After successful completion of value correction, the corrected value is
shown as the display value for ammonium or nitrate the next time the menu
is opened.
The 2-point value correction makes it possible to perform a
subsequent 2-point correction to achieve higher accuracy for a
larger concentration range.
Note: The 2-point value correction and 2-point matrix correction are
comparable from a calculation perspective.
1. Take several samples on various days with different
concentrations, preferably within a week, and perform an
analysis of the samples in the laboratory. During the time the
samples are being taken, the sample temperature should be
around a maximum of 5 °C, as temperature changes are not
taken into account in the value correction.
Note: The 2-point matrix correction concentrations should be within a
range greater than half a decade. The following formula can assist in the
calculation of the half decade:
Conc2
2. Make a note of the two values measured with the sensor in the
samples and displayed for the parameters to be corrected
(ammonium and potassium values, or nitrate and chloride
values).
3. Also note the laboratory value measured for ammonium or
nitrate.
All three values form one of the two correction points.
4. Look for two correction points where the laboratory values are
at least half a decade apart and display typical operating
conditions for the installation.
CALIBRATION > MATRIX
–N or NO –N) that requires
4 3
-N and K correction of the
4
Conc1 x 10
>=
2
Operation
13