Circular filters

Suitable for quantitative analysis.

  • made of pure cellulose with an alpha cellulose content of almost 100 %
  • extremely low ash content (approx. 0.007 %)
  • wet-strength
  • acid-washed

Information about filter grades

  388 Black Spot 389 White spot 391 Blue spot
Applications for coarse and
voluminous
precipitates such as
iron-, aluminium- and
chromium hydroxide,
Si-determination in
steel and pig iron
analysis
coarser precipitates
such as lead-, iron-
and silver sulphide,
alcali carbonates, food
stuff and soil analysis
fine-grained precipitates
such as barium sulphate,
metastannic acid, cuprous
oxide
Filtration properties fast filtering
wide pores
soft, lose structure
coarse crystalline
medium fast filtering
medium pores
medium tight
medium crystalline
very slow filtering
fine pores
very tight
very fine crystallines
Filtration velocity 10 s/10 ml 20 s/10 ml 180 s/10 ml
Filtration time
(Herzberg)
70 s/100 ml
850 ml/min
150 s/100 ml
375 ml/min
2500 s/100 ml
25 ml/min
Basis weight 84 g/m2 84 g/m2 84 g/m2
Typical pore size
(Retention range/
recommended
guide)
12 - 15 μm 8 - 12 μm 2 - 3 μm
Cat. No. Diameter Grade Unit
6759115 125 mm 388 Black spot 100
6759116 150 mm 388 Black spot 100
       
6759215 125 mm 389 White Spot 100
6759216 150 mm 389 White Spot 100
       
6759315 125 mm 389 Blue Spot 100
6759316 150 mm 389 Blue Spot 100
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