wtw AmmoLyt 700 IQ, Руководство по эксплуатации

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Calibration and measuring AmmoLyt
®
700 IQ
4 - 14 ba75353e05 03/2006
Concentration and
quantity of standard
solution
The concentration and quantity of the standard solution to be added
depend on the measuring range expected. They can be determined by
means of the following diagram. The requirements for the simple stan-
dard addition are automatically met while doing so.
V
P
:V
S
is the volume ratio between the test sample and standard to be
added. If several combinations for concentration/volume ratio (bars)
are possible for the determination, select the bar where the expected
NH4-N concentration is more in the center.
Example:
The expected average concentration is approx. 3.5 mg/l NH4-N. The
vertical line in the diagram crosses three ranges:
– Concentration 1 g/l and volume ratio 200:1
– Concentration 1 g/l and volume ratio 100:1
– Concentration 10 g/l and volume ratio 500:1
Selection of the range: Basically, all of the three ranges are suitable.
The lower bar is crossed by the line on the right edge only. There-
fore, the other two ranges are better suited. For further selection,
decide which bar covers the expected measuring range better, i.e.
whether the expected values are rather lower or higher than the ave-
rage value. Besides, the decision can be made according to practi-
cal points of view (availability of standard solution and suitable
dosing equipment).