Ahlstrom Grade 642 Qualitative Filter Paper
Ahlstrom Grade 642 Fast Flow Filter Paper. This grade has finer particle
retention than Ahlstrom 601 but with slightly lower filtration speed.
Grade 642 also has higher absorption than Ahlstrom 601. It is used in
general laboratory applications to retain particles above 2µm in size.
Grade 642 is also found in agricultural and environmental laboratories
for plant growth trials, soil testing, and air analysis for monitoring
specific contaminants and in the filtration of organic and sulfide