Metrohm MVA-20 - Manual (Page 9)

Application Bulletin 402/1 e
Installation instruction for MVA-20
4.1.5. Rinsing measuring vessel
After each sample the measuring vessel need to be rinsed
with deionized water. The rinsing and draining times depend
on the total volume used in the determination.
If the method templates are used, the rinsing and draining
times are defined in the corresponding PUMP commands in
the TRACK – R INSE and TRACK – D RAIN . The number of
rinsing cycles is defined in the command LOOP – LOOP
R INSING in the TRACK – R INSING CYCLES .
Fig. 11: Method snippet TRACK – R INSING CYCLE
Examples for rinsing and draining times:
Cell volume 50 mL 100 mL
Number of rinsing cycles 2 2
Draining time [s] 35 50
Rinsing time [s] 9 18
Please note! The device assigned to the commands PUMP
– PUMP R INSE und PUPM – PUMP D RAIN need to be the
919 IC Autosampler plus, since the 843 Pump Station is
connected to and controlled from the sample changer.
4.1.6. Rinsing transfer tubing
This only applies for the brightener determination by MLAT!
After each sample the transfer tubing from the 919 IC
Autosampler plus to the measuring vessel of the 894
Professional CVS need to be rinsed with deionized water.
The rinsing solution is placed in a vial on the rack of the 919
IC Autosampler plus. The position of the rinsing solution
relative to the sample position is defined in the TRACK – G O
TO RINSING POSITION in the command MOVE – MOVE R INSING
POSITION .
Fig. 12 Method snippet TRACK – G O TO RINSING POSITION
To change the relative position of the rinsing solution the
formula editor has to be used on the parameter «Number»
in the section «Target» in the command MOVE – MOVE
R INSING POSITION .
Fig. 13 Formula editor to change the rinsing position
The transfer time for the rinsing solution corresponds to the
sample transfer time defined in the TRACK – P ERISTALTIC
PUMP in the command PUMP – P ERISTALTIC PUMP ON.
4.2. Evaluation
Settings regarding evaluation and documentation of the
determination are located in the «Evaluation» part of the
method. The templates already include all necessary
settings to determine brightener or suppressor concentration
in an acid copper bath. If modifications however should be
necessary, here is where important parameters are found:
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