FRITSCH ANALYSETTE 3 PRO - Manual (Page 10)

CAUTION!
The conversion of the "ANALYSETTE 3 PRO" to the micro
mill "PULVERISETTE 0" cannot be recommended, as the
amplitude control is unusable due to the ball collision mal-
functions and therefore has no utility value. In this case, the
"ANALYSETTE 3" SPARTAN is more suitable.
However if you are using the PRO version with the PULVERI-
SETTE 0 grinding attachment, note that the amplitude must
not be set to > 2 mm, as otherwise damage will be caused
to the device, for which we accept no responsibility.
The "ANALYSETTE 3 SPARTAN" is equivalent in design to the PRO model,
except that the range of functions is limited. The serial interface, elec-
tronic amplitude control, amplitude display, interval time specification,
micro sieving option as well as the standby function are not included.
2.2.1 Operating principle
The plastic housing contains a solid cast structure with an electronically
controlled electromagnet. Three permanently flexible flat springs carry
the pole plate of this magnet together with the vibratory plate, which is
fastened to it. When the magnet is switched on, the pole plate and vibra-
tory plate are attracted and spring back when it is switched off. The cast
structure and magnet on one side and the pole plate, vibratory plate and
sieves on the other side form a vibratory system.
The different number of sieves and sieving stocks or grinding attach-
ments changes the natural frequency of the vibratory system. For this
reason, it is not always possible to set the amplitude of the sieve shaker
optimally e.g. with a constant 50 Hz mains frequency present. The pro-
cessor-controlled electronics of the ANALYSETTE 3 PRO sieve shaker
ensures a precisely adjustable, reproducible sieve amplitude. This is ach-
ieved by bringing the frequency to stimulate oscillation closer to the nat-
ural frequency of the system or farther away from it. The desired oscilla-
tion amplitude of the sieve stack between 0.1 mm and 3.0 mm can
always be achieved - and with relatively low energy input. Therefore,
continuous operation is possible without heating the sample material
and the overall sieve system.
2.2.2 Amplitude control
An electronic control circuit guides the sieve frequency of the ANALY-
SETTE 3 PRO from a high to a low frequency range. In the meantime, a
measuring system records the amplitude and reports it to the control cir-
cuit until the preselected amplitude is reached.
This amplitude control takes place at regular intervals during the entire
operation. This makes it possible to react to changes in the sieve system.
Safety information and use
- 10 -