Operation
Pges
2 - 18
ba43121e03
01/2011
2.6.2
Carrying out a manual correction
Principle
The concentration of total phosphate is measured in a representative
sample using
(at the same time and place if possible)
a selected
comparison procedure (e. g. a laboratory photometer and WTW
reaction cell test) and the TresCon Pges. The measured value from the
comparison procedure is entered as the nominal value for TresCon
Pges. From the nominal value and its own measured value, TresCon
calculates a correction factor (delta) that is used for all further
measurements.
Process instructions for
the comparison
measurement using a
laboratory photometer
For sampling and measurement, perform the following steps:
z
Open the overflow vessel of the TresCon Pges.
z
Using a pipette, carefully take the required amount of sample for the
comparison measurement. Make sure no sediment is dispersed and
sucked in. The level of the liquid should not sink below the catch
point of the sample (fitting of the sample tube).
z
Close the overflow vessel of the TresCon Pges.
z
Immediately afterwards start a measuring procedure on the
TresCon Pges.
z
After the measuring procedure is completed call up the
Parameters
AutoKorr
menu. Leave the TresCon in this mode until Cnom is input
so that the determined measured value is not overwritten by
following measured values (sampling at the same time).
z
Perform a comparison measurement (determine Cnominal), e. g.
using a laboratory photometer according to the following process
instructions.
z
Enter Cnom in the menu,
Parameters AutoKorr
of the TresCon
Pges.
Suitable
WTW cell test
Process instructions for
the comparison
measurement
(determination of
Cnominal)
Proceed as follows to determine Cnominal:
Concentration
WTW test
0.05 to 5.00 mg/L Pges
P6/25
0.05 to 5.00 mg/L Pges
14543
1
Measure the sample with the photometer: Perform at least 5
tests according to the operating manual of the photometer.
Note: Before starting the new measurement series, determine
a new reagent blank value.
2
Calculate the average value from the tests:
Cnominal
Sum of the measured values
Number of measured values
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