Hach AN-ISE sc Addendum To The Operator Manual page 11

Correction option Application
A 1-point matrix correction is the most commonly used correction option and performs a 1-point
matrix correction for ammonium and/or nitrate
matrix correction as the first correction. The 1-point matrix correction can be performed both with
1-point matrix and without correction of the compensation electrodes (potassium or chloride); in most cases, it is
correction sufficient to perform it without correction. A correction featuring potassium and/or chloride is only
necessary if a high level of accuracy is required. With a 1-point matrix correction, a sample must be
taken when the correction is triggered and analyzed in the laboratory. The 1-point matrix correction is
activated when the laboratory value is entered.
1-point value correction (correction at one concentration point) corresponds to a 1-point matrix
correction with an alternative entry format.
1-point value
correction
Comparison values between the ISE probe and the laboratory can be collected over a period of
around a week with this correction. The correction can be performed at a later stage.
2-point value correction (correction at 2 different concentration points) should be performed if
dynamic concentration fluctuations are present over at least half a decade
2-point value
matrix correction or 1-point value correction does not achieve a sufficiently accurate result.
correction
Comparison values between the ISE probe and the laboratory can be collected over a period of
around a week with this correction. The correction can be performed at a later stage.
The 2-point matrix correction corresponds to a 2-point value correction, but uses an
alternative entry format and is recommended if there is a dynamic process with a large
2-point matrix
nitrate/ammonium fluctuation greater than at least half a decade
correction
sample must be taken for both points when the correction is triggered and analyzed in the laboratory.
The 2-point matrix correction is activated when the laboratory value is entered.
Return to one of the last matrix and value corrections performed if a correction has not produced
Previous corrections
a successful result.
1
Examples of half a decade: The concentration of nitrogen nitrate shifts between 1 and 5 mg NO
between 5 and 25 mg/L NO
4.3.4 Performing the matrix correction
4.3.4.1 1-point matrix correction
Calibration
Matrix correction
More corrections
Information
English
Table 1 Correction options for ISE probes
–N. (conc2 = (conc1 x 10)/2)
3
Note: Take laboratory value measurements or reference values promptly
or, alternatively, take these from the stabilized sample. This will prevent
changes in sample concentration, as time is a factor in comparative tests.
Refer to
laboratory measurement tests.
Proceed as follows to perform
1. Select
CALIBRATION > 1-point matrix correction
2. Select
press
3. Select the parameters you wish to correct and confirm by
pressing
Selection options for AN-ISE sc:
NH
Selection options for AISE sc:
NH
(4.3.4.1, page 11). It is advisable to perform a 1-point
7.3 Validation accessories, Page 39
1-point matrix correction
SENSOR MENU > AN-ISE SC
2-point matrix correction
.
ENTER
.
ENTER
+ NO ; NH ; NO ; NH
4 3 4 3 4
; NH + K
4 4
Operation
1
and a 2-point
1
. With a 2-point matrix correction, a
–N or
3
for recommended
:
or or
AISE SC NISE SC >
.
from the selection window and
+ K; NO + Cl; NH + K NO
3 4
+ Cl
3
11