FRITSCH PULVERISETTE 7 premium line - Manual (Page 37)

CAUTION!
Never operate the device without material to be ground,
otherwise the grinding balls and grinding bowl will be dam-
aged.
5.6 Factors with an impact on grinding
5.6.1 Running time (grinding duration)
A longer grinding duration will increase the percentage of fine material.
To reduce the running time, you can use a grinding bowl and grinding
balls with a higher density, and thus a higher impact energy.
5.6.2 Speed
Higher speeds shorten the grinding time and increase the share of fine
particles.
5.6.3 Reverse mode
NOTICE!
The grinding duration in the reversing mode must not
exceed 5 minutes. A longer grinding duration in the
reversing mode may damage the PULVERISETTE 7 premium
line.
Useful for mechanical alloying.
Improvement of the homogeneity of the sample.
The grinding duration of a grinding cycle in reversing mode must not
exceed 5 minutes. The overall duration is determined by the number of
cycles.
Overall grinding duration = time x cycles
5.6.4 Number and size of the balls
Pre-grind course, hard material with large balls:
reduced percentage of fine material!
Many small balls increase the percentage of fine material during
extended running time.
Using the device
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