Grade |
Comments |
Weight (g/m2) |
Thickness (mm) |
Flow Time*1 (sec) |
Absorption speed*2 (cm) |
Wet Strength*3 (kPa) |
Nominal Rating (µm) |
Collection Efficiency (%, 0.3
|
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
|
-
|
*1. Flow time is the time in seconds required to filter 100 mL of distilled water at 20°C under pressure supplied by a 10 cm water column through a 10 cm2 section of filter paper.
*2. Absorption speed is the distance in cm that water will travel in an upright strip of filter paper in ten (10) minutes at 20°C.
*3. Wet strength is the pressure measured by Mullen Burst Strength Tester after soaking in water.
*4. Conversions between manufacturers are not absolute. Use these conversions as a guideline.
| mm | No. 3 | No. 5A | No. 5B | No. 5C | No. 6 | No. 7 |
| 55 | 0.03 | 0.02 | 0.03 | 0.03 | 0.02 | 0.02 |
| 70 | 0.04 | 0.04 | 0.04 | 0.05 | 0.04 | 0.03 |
| 90 | 0.07 | 0.06 | 0.07 | 0.08 | 0.07 | 0.06 |
| 110 | 0.11 | 0.09 | 0.10 | 0.11 | 0.10 | 0.08 |
| 125 | 0.14 | 0.12 | 0.13 | 0.15 | 0.13 | 0.11 |
| 150 | 0.20 | 0.17 | 0.19 | 0.21 | 0.18 | 0.15 |
| 185 | 0.30 | 0.26 | 0.29 | 0.32 | 0.28 | 0.23 |
| (µg/g) | Si | Na | K | Ca | Mg | Fe | Pb | Cu | Mn | Ni | Al | Zn | Cd |
| Qualitative | 46 | 62 | 3 | 140 | 17 | <5 | <1 | <1 | <1 | <1 | <2 | 1 | <0.5 |
| Quantitative | 32 | <10 | <2 | <10 | <1 | 8 | <1 | <1 | <0.5 | <1 | 2 | <1 | <0.5 |
Malaysia
