FRITSCH PULVERISETTE 25 - Manual (Page 30)

page 29
PULVERISETTE 25
4.3 Grinding Process with the Protected Funnel
1. Set the main switch (19) on the back of the instrument to I (ON).
2. Close the cutting mill (see chapter 4.1.6).
3. Insert the collecting vessel (8).
4. Pull out the sample pusher (24) fully.
5. Move the piston (23) into the lower position.
6. Open up the funnel lid (21), add some grinding material and
close the lid again.
The quantity of material to be ground will depend on the feed
grain size and the grindability of the material. It is best to start
with small quantities and increase the quantity depending on
the success of the grinding process.
7. Switch on the instrument Æ Press the green Start button
(chapter 0).
8. Move the sample pusher (24) to the right in the direction of the
piston (23) until the material to be ground is in front of the
piston (23).
9. Pull the piston (23) upwards, and move the sample pusher
(24) to the right until the material to be ground drops into to
the grinding chamber (slight grinding noise will be heard).
10.Leave the sample pusher (24) at the right, and move the
piston (23) downwards (grinding noise will become louder).
11.Push the piston (23) up/down. This pumping results in air
being sucked in and pumped out by the air filter on the right-
hand side of the machine.
The air movement is critical to ensuring the fine material
passes through the sieve for collection while the larger
particles are returned for reprocessing.
12.The grinding operation is finished when the grinding noise
becomes quieter.
13.Further material to be ground can then loaded into the
machine as above.