Metrohm 717 Sample Changer - Manual (Page 9)

2.3 Arranging the Accessories
717 Sample Changer, Installation 7
2.3 Arranging the Accessories
2.3.1 Setting up the Rinsing Equipment
To mount the PTFE tubings to the pump inlets or outlets enlarge it
carefully using a screwdriver, a pen or another appropriate tool. A
piece of sand paper facilitates grasping of the tubing.
The arrangement of the tubing depends on the rinsing equipment.
Rotating nozzle
Using a changer model with one pump per tower only, the rotating
nozzle (6.2740.000) is recommended for rinsing. The Teflon tubing
is then directly connected to the rinsing pump (pump 1). The dis-
tribution head may be dismounted in this case.
Place the rotating nozzle vertically in the titration head with the aid
of a SGJ14/12 mm sleeve.
Spray nozzles
When using a changer model with two pumps per tower, spray
nozzles (6.2740.020) may be used in combination with an aspira-
tion tip M8 (6.1543.170). Insert the spray nozzles into the sloped
borings of the titration head. Use Teflon tubings to connect them
to the distribution head. Each of the four outlets of the distribution
head must be plugged. Plug unused outlets with an M6 thread
stopper (6.1446.040) to avoid splashing of liquid during rinsing.
Fix the tubings in the guide chain. Chain links may be removed if
necessary (see below).
Insert the aspiration tip vertically into a boring (SGJ9) of the Macro
Titration head. The Micro Titration head offers also a vertical bor-
ing for the placement of the aspiration tip. Connect the tip with the
Teflon 4/6 tubing (6.1805.510) and a screw connector 4/6 mm
(6.1820.030) to pump 2 (valve marked with 'ê'). During the rinsing
procedure, first the sample is sucked off then the electrode is
rinsed in the empty vessel.