Metrohm 751 GPD Titrino - Manual (Page 205)

4.2. Diagnosis
751 GPD Titrino
202
• Press <Start>.
The internal dosing unit expells twice the volume of 3.5 ml.
• Remove exchange unit.
• Check spindle zero position, see Fig. 6.
0.2 - 0.6 mm
Fig. 6 Fig. 7
The spindle must be 0.2 - 0.6 mm below the edge of the sliding plate.
The bar of the stopcock coupling must be exactly parallel to the lateral edges of the
GPD Titrino, see Fig.7.
• Reinsert Exchange Unit.
Titrino fills.
The display of before reappears.
• Knob 'dV/dt' to right stop.
• Press the <DOS> key (on instrument) until the piston rod reaches the top and at the same
time measure the time from start to end.
XXX X ********
cylinder empty !
mind selected language!
Spindle remains at maximum position. The transit time of the spindle is 20 s.
• Measure spindle lifting (can be performed only if the 3.496.0070 Dummy Exchange Unit is
inserted or the locking switch (in right hole) is carefully operated with a screwdriver after
removal of the Exchange Unit).
From the start point, the spindle travels 80 mm. Instead of the spindle height, the ex-
pelled volume can be measured (corresponds to max. vol. of Exchange Unit used).
• Press <FILL> (on instrument) and simultaneously measure the time until the GPD Titrino
is again in the 'ready' position.
Times for filling: per stop cock cycle 1 s
for filling 20 s (Tolerance: 10 %)
The following generally holds: Spindle and stopcock must move at a constant speed
(noise!). In the filling setting, the stopcock coupling must position the lever of the
Exchange Unit correctly at the left stop (with virtually no play and without sticking).
• Set potentiometer 'dV/dt' to left stop.
• Press <DOS> (on instrument) at same time and use a stopwatch to measure the time for
1
/ 10 of the cylinder volume to be expelled. The time should be ca. 76 ... 126 s.
• Set potentiometer 'dV/dt' to right stop.
• Press <FILL>.