Metrohm 730 Sample Changer - Manuel (Page 61)

3.6 User Methods
730 Sample Changer, Introduction 58
Method: tower1+2
This method allows titration of each sample using two different titration methods, one
after the other, with the 2-tower model of the 730 Sample Changer (with 2x2 pumps)
and 2 Titrinos. An auxiliary solution can also be added according to the titration
method used. A 685 Dosimat or a 700 Dosino can be connected via the External Bus
interface (and 729 Dosimat Interface) for this purpose. A 12 or 24-position rack is re-
quired for parallel titration. At tower 1 the electrode is rinsed after the titration. At
tower 2 the sample solution will be aspirated after the titration.
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730 Sample Changer 0120/02 187 730.0013
parameters
method tower1+2
number of samples: rack
>start sequence
1 CTL:Rm: INIT
2 MOVE 1 : sample
3 LIFT: 1 : work mm
4 STIR: 1 : ON s
5 CTL:Rm: START device1
6 SCN:Rm : Ready1
7 STIR: 1 : OFF s
8 LIFT: 1 : rinse mm
9 PUMP 1.1 : 2 s
10 WAIT 5 s
>sample sequence
1 MOVE 2 : sample
2 LIFT: * : work mm
3 STIR: * : ON s
4 DOS: 1 : 15 ml
5 WAIT 5 s
6 CTL:Rm: START device*
7 SCN:Rm : Ready*
8 STIR: * : OFF s
9 LIFT: 1 : rinse mm
10 PUMP 1.1 : 2 s
11 PUMP 2.2 : 15 s
12 PUMP 2.* : 4 s
>final sequence
1 MOVE 2 : sample
2 LIFT: 2 : work mm
3 STIR: 2 : ON s
4 DOS: 1 : 15 ml
5 WAIT 5 s
6 CTL:Rm: START device2
7 SCN:Rm : Ready2
8 STIR: 2 : OFF s
9 PUMP 2.2 : 15 s
10 PUMP 2.
∗ : 4 s
11 MOVE 1 : spec.1
12 LIFT:
∗ : work mm
>changer settings
rack number 0
lift rate 1 25 mm/s
lift rate 2 25 mm/s
shift rate 20
shift direction: +
beaker test mode: both
on beaker error: display
>stirring rates
stirrer 1 3
stirrer 2 3
stirrer 3 3
stirrer 4 3
>dosing unit def.
>manual stop
…
——— titrate first sample at tower 1 ———
- start first titration
- wait for end of titration (static 'ready'-Signal)
- rinse with rotating nozzle
— parallel titr. of 2 samples at 2 towers simultaneously —
- sample in front of tower 2 (next sample at tower 1)
- both lifts in work position
- switch on all stirrers
- add aux. solution (according to tubing arrangement on
tower 1 or 2)
- both Titrinos start titration
- wait for end of titration at both Titrinos (static 'ready'-
signal)
- rinse with rotating nozzle on tower 1
- suck off sample solution at tower 2
- rinsing and aspiration (with spray nozzles) at tower 2
——— treat last sample separately ———
- immerse electrodes in conditioning beakers spec.1 and
spec.2
- turning direction of the rack is always ascending
- test for missing beakers at both towers
- if a sample beaker is missing, issue a message