wtw NitraLyt 700 IQ, Operating Manual, Page: 36 / 61

Calibration and measuring NitraLyt
®
700 IQ
4 - 16 ba75397d03 12/2004
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
NO3-N concentration is more in the center.
Entry of volumes The volume of standard to be added in this calibration procedure has
to be entered on the terminal of the IQ S
ENSOR
N
ET
with an accuracy
of 1/10 ml. Therefore, the volume has to be rounded up or down
accordingly.
Example:
The expected average concentration is approx. 0.9 mg/l NO3-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
average value. Besides, the decision can be made according to
practical points of view (availability of standard solution and suitable
dosing equipment).