BUCHI Multivapo P-12 - Manual (Page 48)

6 Operation
48 Multivapor™ Operation Manual, Version E
6 .2 Sample preparation
6 .2 .1 Heating up the instrument
Distilled water is added to each glass cylinder
on the crystal rack to transfer the heat from the
heating plate to the sample tube. Equal amounts
of water must be added to each cylinder to
provide a uniform heat transfer. A level indication
designates the optimum volumes depending on
the type of sample tube.
Turn on the heating as soon as each position
is filled. It takes approximately 20 min to equili-
brate the system, i.e. until the water temperature
remains constant.
Fig. 6.30: Filling distilled water to a level where strong agitation during operation is obtained
NOTE
• The water volume is the decisive parameter for optimal heat transfer, therefore it is not advisable
to add too much water. Heat transferred into the sample decreases with an increasing volume.
This is mainly the result of insufficient mixing of the heating medium. Therefore, fill in only as much
water so that the sample vessel dips into the heating medium by 2 to 3 cm. Optimize the rotation
to obtain a vigorous vortex for both the sample and the heating medium.
• To reach equilibrium turn on the instrument and set it to the desired evaporation temperature
20 min prior to the distillation process.
6 .2 .2 Sample preparation
NOTICE
Risk of lifetime shortening of the adapter seals and the quick lock nut.
• Fix all connections only hand tight.
• Avoid overtightening.
The installation and sealing of the sample tube is carried out as follows:
• Use the Multivapor tool for removing the
insert of the adapter and for changing the
gasket.
• Use the optional PE frits for foam and splash
protection.
• To remove the optional PE frits from the tube
adapter, push a thin object from the top
through the hole.