Top IPC subclasses
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1
|
C02F
|
3
|
Treatment of water, waste water, sewage, or sludge
|
|
2
|
B04B
|
2
|
centrifuges
|
|
3
|
C01B
|
2
|
non-metallic elementscompounds thereof
|
|
4
|
H05B
|
2
|
electric heatingelectric lighting not otherwise provided for
|
|
5
|
G01F
|
2
|
measuring volume, volume flow, mass flow, or liquid levelmetering by volume
|
|
6
|
B01J
|
2
|
Chemical or physical processes, e.g. catalysis, colloid chemistry; their relevant apparatus
|
|
7
|
B01D
|
1
|
Separation
|
|
8
|
C07D
|
1
|
Heterocyclic compounds
|
|
9
|
C07F
|
1
|
acyclic, carbocyclic, or heterocyclic compounds containing elements other than carbon, hydrogen, hal
|
|
10
|
G01J
|
1
|
measurement of intensity, velocity, spectral content, polarisation, phase or pulse characteristics o
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