Labconco CentriVap Centrifugal Concentrators and Cold Traps 74750 Series - Manual (Page 21)

Chapter 4: Using Your CentriVap
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Loading Glassware into the CentriVap
Smooth operation of the CentriVap is dependent upon proper balance of the
machine. Therefore, if less than a full load of samples is run, it is important to
load samples into the CentriVap in a fairly symmetrical manner distributing the
weight of the samples evenly in the sample rotor.
Temperature Setting Guidelines
The evaporation rate achieved by the CentriVap is dependent upon a variety of
factors. These include the nature of the solvent, the temperature and the pressure
in the vacuum system.
As a general guideline, to speed the evaporation process, the CentriVap
temperature should be set as high as possible as long as the temperature will not
damage the sample or cause the sample to bump.
Time Setting Guidelines
The CentriVap Concentrator has two timers. The “RUN TIME” turns the entire
concentrator off after the user set period of time. This stops the rotation, turns off
the heater and vacuum pump and bleeds vacuum from the system. The heater
may be turned off prior to the concentrator turning off so heat-sensitive samples
may be protected from exposure to excessive heat after the solvent has
evaporated. To turn the heater off prior to stopping the entire system, enter a set
time into the memory at the “HEATER TIME.” When the programmed time
expires, the heater will turn off but the rotation and vacuum will continue until the
run time expires.
The tables in Appendix C: CentriVap Specifications indicate approximate times
required to evaporate various common solvents. Actual times must be determined
by the user. The CentriVap can be set to alarm after a preset period of operation.
When the time expires, the CentriVap will give an audible alarm and turn itself
off.
Heat Boost Operation
Some CentriVap models are equipped with a secondary “Heat Boost” heater,
which is positioned on the sidewall of the chamber near the top. It provides
additional heat to the samples to speed evaporation. The “Heat Boost” heater is
controlled by the microprocessor to maintain the set point temperature at the
bottom of the chamber to prevent excessive overheating of the samples.