Metrohm MVA-20 - Manual (Page 11)

Application Bulletin 402/1 e
Installation instruction for MVA-20
5.1.3. Course of events
•
The execution of calibration and determination by
dilution titration is controlled by the 894 Professional
CVS and viva.
a) The measuring vessel is emptied using the 843
Pump Station.
b) Dosing Unit «894/D4 2mL Std or sample»
connected to Dosino 4 is automatically rinsed and
prepared with suppressor standard or sample from
the vial on the rack of the sample changer.
c) The measuring vessel is rinsed using the 843
Pump Station.
d) Dosino 1 automatically adds the VMS and Dosino
4 is used for the automatic addition of suppressor
standard or plating bath sample.
e) At the end of each determination the measuring
vessel, is automatically emptied and rinsed using
the 843 Pump Station.
Next sample starts again from a).
•
Recalibration within a determination series is possible.
•
At the end of a determination series Dosino 4 is
automatically prepared with rinsing solution.
5.2. Brightener determination series
5.2.1. Manual operation
•
Dosing Unit «894/D1 50mL VMS» connected to Dosino
1 has to be prepared with VMS.
•
Dosing Unit «894/D2 2mL Brightener» connected to
Dosino 2 has to be prepared with brightener
concentrate.
•
Dosing Unit «894/D3 2mL Suppressor» connected to
Dosino 3 has to be prepared with suppressor
concentrate.
•
Plating bath samples are placed on position 1 to 14 of
the sample rack using the sample vials for 50 mL
(6.2747.010). The exact sample volume needed for the
determination has to be pipetted into the vial.
•
Rinsing solutions are placed on position 15 to 28 of the
sample rack using the sample vials for 50 mL
(6.2747.010). Usually the same volume of deionized
water is used for rinsing like it was used for the sample.
The rinsing solution has to be placed diagonally
opposite the sample on the second half of the circle
(Sample position + 14).
Fig. 16: Example positions of solutions on the sample rack
6.2041.490 for brightener determination
5.2.2. Workplace
•
In the «Run» window on the tab «Determination series»
create a sample table
Fig. 17: Example sample table for brightener determination
•
As sample type S AMPLE has to be selected.
•
For «Sample amount» the volume pipetted into the vial
has to be entered.
5.2.3. Course of events
•
The execution of the determination by modified linear
approximation technique is controlled by the 894
Professional CVS and viva.
a) The measuring vessel is emptied using the 843
Pump Station.
b) The intercept solution is automatically prepared at
the beginning of each determination, by dosing
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