wtw AmmoLyt 700 IQ, Руководство по эксплуатации

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AmmoLyt
®
700 IQ Calibration and measuring
4 - 13 ba75353e05 03/2006
4.1.8 Calibration procedure, Simple std. add. (4)
This calibration with a simple standard addition is carried out in the test
sample while adding standard. The volumes of the test sample and
standard have to be dosed exactly.
The following appliances are suitable for dosing:
!
Measuring cylinder to determine the volume of the sample
!
Pipette (microliter pipette as necessary) for accurate dosing of the
standard. The higher the concentration of the standard, the more
important it is to measure the amount of calibration standard very
carefully.
Note
Before
calibrating, determine the potassium content of the sample (see
section 4.2.2).
Before calibrating, activate the Potassium compens. function and
adjust the potassium content (see section 3.4).
The potassium content of the test sample affects the calibration result.
Conditions and
calibration range for
simple standard
addition
Observe the following points for the simple standard addition:
!
The volume of the standard added to the test sample changes the
test sample. Therefore, the volume of the standard should not be
more than approx. 1 % of the volume of the sample.
Example: With 100 ml sample volume, the added volume should not
be more than 1 ml.
!
Through the addition of standard solution, the ammonium content of
the test sample should be increased at least twofold but not more
than tenfold.
Based on these conditions, the range that can be calibrated is from
0.17 to 76 mg/l NH4-N (or 0.22 to 99 mg/l NH4). If the expected measu-
red values are outside this range, a different calibration procedure has
to be selected.
Cal.: 2 POINT STANDARD (3)
Calibration values for standard 2
determined Confirm with
g
.
Calibration successful
Conc. (NH4-N)
x mg/l
Slope y mV
Drift voltage z mV
End of 2 POINT STAND. (3) cal.
The values for Conc. (NH4-N) ,
Slope and Drift voltage are dis-
played.
The calibration is complete. Con-
firm with
g
.
The display returns to the measu-
red value display.
Displays Explanation