A-96.250.211 / 171121
AMI Sodium P
Product Description
11
2.
Product Description
Application
Sodium measurement is used for quality control in high purity water
applications and to monitor break through of mixed bed ion exchang
-
ers, condenser leaks and the prevention of caustic corrosion of tur
-
bines. The AMI Sodium P is suitable for samples with a pH value
higher than pH7. For samples with a pH lower than pH7, use the AMI
Sodium A.
Measuring
principle
The sodium measurement used in this instrument is based on a
potentiometric measuring method. For this purpose a proven sodium
ion sensitive glass electrode and a reference electrode is used.
These two electrodes produce a different electrical potential which is
used to calculate the sodium concentration of the sample. According
to Nernsts Law, the ion concentration depends on the temperature,
therefore a temperature sensor measures the sample temperature.
With the current temperature the measuring value is expressed for
the standard temperature of 25 °C by using programmed tempera
-
ture compensation curves.
Sodium measurements below 1 ppb require a special glass formula
-
tion for the sensing electrode response. Ammonium and pH interfer
-
ences from the unconditioned sample are eliminated by a suitable
reagent. The measuring limit of 0.1 ppb sodium requires the condi
-
tioning of the sample to a minimum of pH 10.5 while sample integrity
has to be maintained. The best results are obtained with Diisopropyl
-
amine (DIPA).
Signal
Outputs
Two signal outputs programmable for measured values (freely scal
-
able, linear or bilinear) or as continuous control output (control pa
-
rameters programmable).
Current loop:
0/4 - 20 mA
Maximal burden:
510 Ω
Third signal output available as an option. The third signal output can
be operated as a current source or as a current sink (selectable via
switch).
Relay
Two potential-free contacts programmable as limit switches for mea
-
suring values, controllers or timer for system cleaning with automatic
hold function.
Maximum load: 1 A / 250 VAC