No.4A 55mm Quantitative Filter Paper Box 100

Grade

Comments

Weight

(g/m2)

Thickness

(mm)

Flow Time*1 

(sec)

Absorption speed*2 

(cm)

Wet Strength

*3 (kPa)

Nominal Rating (µm)

Collection Efficiency (%, 0.3µm DOP)

Conversion*4

Whatman

ex-Schleicher

& Schuell

No. 3

Ashless

Medium retention (5-10 µm), fast flow rate Analysis of soils, fertilizers, cement, and minerals

113

0.23

130

7.5

12

5

(Medium)

80

43

593-A

No. 5A

Ashless

Fast flow rate, retains coarse particulates and gelatinous precipitates (>10 µm). Filter hydroxides and metallic aerosols, environmental monitoring, determine silica content in steel

97

0.22

60

9.5

10

7

(Coarse and gelatinous)

75

41

589-IH

No. 5B

Ashless

Retains medium particles (5-10 µm) such as CaCO₃, PbSO₄, CaCO₄, MnCO₃, ZnCO₃, ZnS, AgCl

108

0.21

195

7.0

12

4

(Medium)

90

40

589 / 6

Green

No. 5C

Ashless

Collect fine precipitates (<5 µm) such as SrSO₄, BaSO₄, HgCrO₄, and colloidal dispersions; gravimetric analysis

118

0.22

570

6.0

12

1

(Fine)

93

44

589 / 3

Blue

No. 6

Ashless

Retains medium-fine particulates (2-10 µm), trace and precious metals

103

0.20

300

6.0

12

3

(Medium Fine)

90

-

589 / 2

White

No. 7

Ashless

Highest purity for retaining medium particles (5-10 µm), precise gravimetric analysis

87

0.18

200

7.0

10

4

(Medium)

85

-

-

No. 4A

Hardened

High wet strength, suitable for use under high pressure, high chemical and pH resistance, retains fine crystalline precipitates (<5 µm), slow flow

96

0.12

915

4.0

52

1

(Very Fine)

90

50

-