Filling And Zeroing The Handystep S Titrator; Keiner Wärme Aussetzen; Consignes De Sécurité - Grundfos 98842487 Operating Instructions Manual

3.3 Filling and zeroing the HandyStep S
titrator
1. Open the bottle with 2N sodium thiosulphate
solution (titrant) (Fig. 1, Pos. 13).
2. Fill a small amount (approx. 2 ml) into the neutral
tube (Fig. 1, Pos. 12) to prevent contamination of
the solution.
3. Dip the end of the dispenser tip (Fig. 1, Pos. 4)
into the titrant in the neutral tube.
4. Move the locking/filling lever (Fig. 2, Pos. 4)
upwards until its upper stop.
– Titrant is drawn from the neutral tube into the
dispenser tip.
5. Make sure that no air is trapped inside the
dispenser tip.
– To remove air, hold the titrator at an angle and
push and pull the locking/filling lever up and
down a few times.
– Move the locking/filling lever upwards until its
upper stop (see Fig. 4).
0
10
20
30
40
50
60
70
80
90
100
Fig. 4 Top position of locking/filling lever
– The dispenser tip is full of titrant.
6. Hold the end of the dispenser tip over a waste
receptacle or tissue paper. Gently push the
dispensing lever.
– Titrant is discharged from the dispenser tip.
7. Push the dispensing lever, until the bottom of the
locking/filling lever is levelled with the zero mark
on the titration scale (see Fig. 5).
0
10
20
30
40
50
60
70
80
90
100
Fig. 5 Bottom of locking/filling lever levelled
with zero mark
6
– A small quantity of titrant is discharged. The
titrator is primed for titration.
8. Remove any excess titrant from the bottom of the
dispenser tip carefully with a piece of clean tissue
paper.
9. Make sure that the stroke setting wheel (Fig. 2,
Pos. 1) is set to position "1" (see Fig. 6).
Fig. 6 Stroke setting wheel
– Setting the stroke setting wheel to a higher
number increases the quantity of titrant
dispensed per full depression of the
dispensing lever.
The titrator is zeroed and ready to titrate.