Metrohm 711 Liquino - Manual (Page 127)

4. Detailed description
711 Liquino, Instructions for use 121
(cover top of weighing chamber). Place the Erlenmeyer flask on the weigh-
ing pan.
• It is important that the stream of liquid breaks off immediately each time on
dosing. This is why it may be necessary to take special measures for some
cylinder volumes:
2mL: attach a yellow Eppendorf pipet tip to the buret tip. Place
some cotton wool in the Erlenmeyer flask and fasten the buret tip
so that it almost touches the cotton wool.
5, 10, 20 mL: attach a yellow Eppendorf pipet tip to the buret
tip. The stream of liquid should flow against the vessel wall.
50 mL: attach a blue Eppendorf pipet tip to the buret tip. The
stream of liquid should flow against the vessel wall.
•
Dose a few milliliters of the liquid into the Erlenmeyer flask. Allow this to
stand on the weighing pan for some time so that the air in the weighing
chamber becomes saturated with the liquid vapor. This reduces evapo-
ration of the liquid. In addition (for 2 mL cylinders) a small vessel filled
with the liquid and a moistened filter paper may be placed in the weigh-
ing chamber.
• Edit the GLP mode parameters.
In the configuration menu under '>GLP error limits' you can alter the
permitted error limits for the validation results. Individual values can be
selected for each type of dosing unit and cylinder size. The preset set-
tings are recommended values, which you can accept or alter to meet
your requirements.
GLP mode procedure
Tubing and dosing cylinder must be rinsed and filled bubble-free with the
liquid before the actual dosing is carried out. Before starting the GLP mode
it is absolutely essential that the PREP function is carried out.
After pressing the <START> key the operator name, a name for the dosing
drive (Dosino 700) and an unambiguous identification text for the dosing
unit to be validated can be entered. These entries will be printed out later in
the validation report.
You will then be asked to tare the balance. After confirmation with the
<ENTER> key the first dosing will be carried out automatically. The weight
of the amount of liquid dosed in can now be accepted automatically from
the balance or entered manually via the keyboard. The type of weight ac-
yellow pipet tip
cotton wool
plug
yellow pipet tip
blue pipet tip