IKA labworldsoft - Manual (Page 110)

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Cycles
1. n=Number of operating cycles: Here, you can enter how often the process described above is to be
repeated in the experiment sequence.
2. Setp. temp./heating (TH): This is the temperature (or PT100 temperature) up to which the heating
plate is to be heated in the first step. Normally, a temperature of between 20 to 40°C above the
solvent's boiling point is selected to ensure that the solvent is evaporated.
3. Boiling time (tS): This is the time in minutes which is to elapse, after the setpoint
temperature/heating has been reached, before the heating/cooling block is cooled. As shown in step 2,
the solvent must be evaporated during this time and accumulate in the extraction material. (For the
initial experiments, it is advisable to determine this time empirically since it depends on the quantity of
solvent and the properties of the sample and can vary considerably.)
4. Setp. temp./cooling (TK): This temperature is the temperature to which the heating/cooling block is
to be cooled in step 3 in order to achieve the reaspiration effect. The temperature that you select must
not be too low! If the cooling water is not cold enough for the temperature in the block to be reached,
the process will stop at this point. Furthermore, energy is wasted if the block is cooled to a lower
temperature than is necessary since this thermal energy will have to be supplied again for the
following heating process.
5. Filtration time (tF): Here, you enter the time which is to elapse, after the setpoint
temperature/cooling has been reached, to allow the reaspiration process to be performed completely.
Generally, this process is performed rapidly and therefore a short time is sufficient. However, if the
sample is very dense, a longer time must be set.