Metrohm 775 Dosimat - Manual (Page 11)

2.2 Diagnosis
775 Dosimat
7
2.2.5 Diagnosis of spindle drive
1. Insert exchange unit and put the burette tip into a collecting receptacle.
2. Connect push-button cable 6.2107.000 (if available).
3. Knob 'dV/dt' fully to the right.
4. Press feed button 6.2107.000 (if not available, ) all the time until the piston
rod reaches the top position and simultaneously measure the time from start to
stop.
The running time of the spindle is 18 ... 22 s.
General rules:
• Dosimat fills automatically.
• Spindle and cock must move in regular speed (observe sound!)
• In the filling position the cock coupling must turn the lever of the exchange unit blamelessly to the
left stop (almost without play and without jamming).
5. Repeat point 4. and now measure the filling time until the spindle stops at the
lower end.
The running time (filling time) of the spindle is 18 ... 22 s.
6. Knob 'dV/dt' fully to the left.
7.
DOS 0.000 ml
8. Press feed button 6.2107.000 (if not available, ) all the time and simultane-
ously measure the time, until, depending on the exchange unit, the volume in the
table below is reached.
1 ml: 0.02 ml
5 ml: 0.1 ml
10 ml: 0.2 ml
20 ml: 0.4 ml
50 ml: 1
ml
The time must be 14 ... 24 s.
9.
DOS 0.000 ml