multi X 2500
EOX determination
79
NOTICE! Do not exceed the specified amounts of water and glacial acetic acid. Do not
fill the flask up to the 1-liter mark (volume contraction).
Proceed as follows to prepare 100 ml of internal electrolyte (storage solution) for the
sensor:
1.
Dilute 8.52 g of sodium sulfate (Na
2
SO
4
) in 50 ml of ultrapure water in a 100-ml
volumetric flask.
2.
Fill the volumetric flask up to the mark.
The end point routine is used to set the electrolyte to the optimum operating point of
the sensor electrode within the operating range of the titration cell.
Operating range:
lower limit:
1000 counts
upper limit:
10000 counts
optimum operating point:
3000 counts
As soon as the indicator value is outside the operating range of the titration cell, the
system automatically triggers an end point routine. This routine may also be triggered
between two measurements of a multiple determination. The status E
ND POINT ROUTINE
is displayed during the process in the window
STATUS ANALYZER
.
Indicator value greater than 10000:
Silver ions are automatically produced. The value set for the operating point of the
electrolyte is 3000.
Indicator value less than 1000:
The software prompts the user to add a dose of 10 mg/l of HCl to the measuring cell. If
the indicator value rises above 10000, silver ions will be produced automatically and
the electrolyte will be set to an operating point of 3000.
For indicator values within the limits of the operating range (1000 to 10000), the end
point routine can be triggered manually.
The routine is started in the control and analysis software using the menu command
S
YSTEM
E
ND POINT ROUTINE
.
After the end point routine is completed, the window S
TATUS ANALYZER
will show the
current indicator value. The system is ready for measurements.
Preparing internal
electrolyte
Execution of the end
point routine
Automatic end point
routine
Manual end point routine
