BUCHI Multivapo P-12 - Manual (Page 51)

6 Operation
51 Multivapor™ Operation Manual, Version E
6 .4 Distillation
Before operating the system, the following conditions must be fulfilled:
• All electrical connections are established correctly.
• All vacuum and coolant connections are established correctly. The latter being secured with cable
binders.
• All seals are inserted correctly.
• Water is filled in according to the level indication.
To start operating the system proceed as follows:
• Switch on the instrument.
• Set the temperature (recommended: 50 – 80 °C).
• Adjust the coolant flow (recommended: 5 – 20 °C, 600 – 800 mL/min).
• As soon as the instrument is equilibrated (after approx. 20 min), place the sample tubes into the
crystal rack. Use empty sample tubes or blank adapters (optional) to occupy vacant positions.
• Close the vacuum cover and screw it hand tight.
• Set the rotational speed (recommended: pos. 8 - 10).
• Turn on the vacuum pump and controller.
• Set the vacuum according to the 25/20 °C rule.
• Wait approx. 5 min after the vacuum has reached the set point. The temperature of the sample
may, depending on the set temperature, drop during initial evaporation, resulting in a slight subse-
quent readjustment of the vacuum conditions.
• If the distillation does not start, carefully reduce the vacuum gradually or increase the tempera-
ture at the instrument. Check the efficiency of the condenser and make sure that the vapor is not
directly sucked into the pump.
NOTE
In general the smaller the test tubes the higher the risk of boiling retardation. In order to prevent
contamination of the vacuum cover apply a pressure gradient to reduce the pressure gradually (see
chapter 6.5.2) and/or use the optional PE frits as splash and foam protection.
6 .5 Optimizing the vacuum conditions (optional)
There are three distinct ways to evaporate multiple samples in parallel with the Multivapor using
either the Vacuum Controller V-850 or V-855. The main functions are described briefly in the following
sections. For further information please consult the corresponding Operation Manual.
6 .5 .1 Manual vacuum control and solvent library (V-850/V-855)
Choose the temperature according to the 25/20 °C rule. The corresponding pressure is best derived
from the Solvent Library. This is achieved as follows:
• Open the Solvent Library. • Select the corresponding
solvent.
• Set the instrument tempera-
ture.