Metrohm 746 VA Trace Analyzer - Manual (Page 179)

5.3 Set Up
746 VA Trace Analyzer / 747 VA Stand
5-28
Softkeys Meaning
Prime
tube
Fill transfer tubing
By pressing this softkey the transfer tubing is automatically refilled
with hydraulic solution. This may be necessary in two cases:
• For filling empty transfer tubing.
• For expelling interfering air bubbles.
For further details, please see the 695 Instructions for use.
Cond.
tube
Clean transfer tubing
Contamination of the transfer tubing is normally shown by breaking up
of the air bubbles used to separate the solutions, i.e. they are no
longer durable. In this case, an attempt can be made to free the
transfer tubing from contamination using a cleaning solution, prefera-
bly Javelle water (hypochlorite solution). Proceed as follows:
• Press . The transfer needle is moved to a posi-
tion in front of the 747 VA Stand, at the same time the prompt
Put solution on cond. position appears.
• Position a vessel containing sufficient Javelle water below the
transfer needle.
• Press . The transfer tubing is filled with Javelle
water. After a wait of 1 min., the transfer needle is moved to
the waste position and the solution expelled
• Repeat the entire procedure once more.
For further details, please see the 695 Instructions for use.
Rinsing
Dosinos
Switch to Rinsing Dosinos
The measuring vessel at the 747 VA Stand are rinsed by means of two
700 Dosinos with 50 mL dosing units screwed to supply containers,
one of which adds the rinsing solution while the other siphons off any
wash solutions into the waste container. This softkey is used to switch
to the manual operation of the two rinsing Dosinos. The following
functions are available:
Rinse
meas.v.
Rinse measuring vessel
After this softkey has been pressed, the measuring vessel is auto-
matically rinsed as follows:
• The solution in the measuring vessel is siphoned off.
• The measuring vessel is filled with the volume of rinsing solu-
tion defined as
V.rinse .
• The rinsing solution is siphoned off.
• The measuring vessel is filled with the volume of rinsing solu-
tion defined as
V.standby (conditioning solution).
Prime
Dosinos
Initialize rinsing Dosinos
The burette cylinders of the rinsing Dosinos and all connecting tubing
up to the measuring vessel and the wash station are automatically
filled with rinsing solution.
Empty
Dosinos
Empty Dosinos
The burette cylinders of the rinsing Dosinos, the wash station and all
connecting tubing up to the measuring vessel and the wash station
are emptied.