Metrohm 797 VA Computrace - Manual (Page 234)

8 How to ...?
797 VA Computrace – Software
222
Typical standard addition scheme for "DT Suppressors with
calibration curve":
1. Choose a previously recorded Calibration curve on
the Determination tab of the EDIT WORKING
METHOD PARAMETERS window. Use the
button to search for the Calibration curve file. “Addi-
tion ratio” and “Evaluation ratio” are set automati-
cally to the values used for recording the calibration
curve.
2. Place the VMS (Virgin Make-up Solution) into the
sample vessel and click on start. Q(0) is determined.
3. Add “Production bath solution” and measure
Q(addition) for each addition, until Q/Q(0) < “Addi-
tion ratio”.
Response-Curve-Technik
"RC Sample with response curve", and "RC Record response
curve" to record the response curve.
The “response curve technique” is used for the determination of
suppressor. It should be applied, if the "dilution titration techni-
que" is inapplicable. It consists of two measurement parts:
A. "RC Record response curve”
This Calibration technique is used to determine the Suppres-
sor concentration. That is done by addition of a Suppressor
standard solution containing a known Suppressor con-
centration to an Electrolyte solution.
Typical standard addition scheme for "RC Record response
curve":
1. Place the Electrolyte sulution into the sample vessel
and click on start. Q(0) is determined.
2. Add Suppressor standard solution and measure
Q(addition) for each addition.
B. "RC Sample with response curve”
This Calibration technique wird zur Bestimmung der Supp-
ressor-Konzentration verwendet.
1. Wählen Sie eine vorher aufgenommene "Response
Choose a previously recorded Response curve on the
Determination tab of the EDIT WORKING METHOD
PARAMETERS Fensters. Use the button to
search for the response curve file.
2. Place the Electrolyte sulution into the sample vessel
and click on start. Q(0) is determined.
3. Remove the Electrolyte sulution.