Hoskin EnvironmentalSampling and monitoring instruments for air, water, weather and soil for the environmental, agricultural, mining and research markets.
Hoskin GeotechnicalMaterials and Product testing for soil, asphalt, petroleum, concrete, mining, cement, and research industries.
Hoskin InstrumentationSensors, transducers and instrumentation for industry, manufacturing, research and development and factory automation.
Equations for conversion of kinematic viscosity or viscosity into other viscometric units are given here. All data must be at 25°C. Note that the equations apply only between the minimum and maximum drain times shown. While the equations in the table below are widely used, the equation v = at – b/t is often more […]
Contact us for details
Equations for conversion of kinematic viscosity or viscosity into
other viscometric units are given here. All data must be at 25°C. Note
that the equations apply only between the minimum and maximum drain
times shown.
While the equations in the table below are widely used, the
equation v = at – b/t is often more applicable, especially at low flow
times and low kinematic viscosity.
Viscosity Standards for Zahn, Shell, and Ford Cups
| Viscosity Standard |
Kin Vis mm2/s (cSt/s)
|
Zahn Cup
|
Shell Cup
|
Ford Cup
|
|||
|
Size
|
Drain time, sec
|
Size
|
Drain time, sec
|
Size
|
Drain time, sec
|
||
|
C6 |
8.9
|
–
|
–
|
1
|
52
|
–
|
–
|
|
C10 |
17
|
1
|
45
|
2
|
35
|
1
|
70
|
|
C20 |
34
|
1
|
60
|
2
|
64
|
2
|
42
|
|
2½
|
40
|
–
|
–
|
||||
|
C35 |
66
|
2
|
33
|
2½
|
74
|
2
|
64
|
|
3
|
46
|
3
|
35
|
||||
|
3½
|
32
|
–
|
–
|
||||
|
C60 |
120
|
2
|
48
|
3½
|
57
|
3
|
58
|
|
4
|
36
|
4
|
36
|
||||
|
C100 |
230
|
3
|
27
|
4
|
68
|
4
|
64
|
|
4
|
21
|
5
|
36
|
–
|
–
|
||
|
C200 |
460
|
3
|
47
|
5
|
72
|
5
|
40
|
|
4
|
36
|
6
|
29
|
–
|
–
|
||
|
C350 |
850
|
4
|
62
|
6
|
53
|
5
|
70
|
|
5
|
37
|
–
|
–
|
–
|
–
|
||
|
C600 |
1600
|
5
|
70
|
–
|
–
|
–
|
–
|
|
Cup Number
|
Equations* where
t = Time of flow, seconds v = kinematic viscosity, mm2/s |
Drain time seconds
|
Kinematic viscosity centistokes
|
||
|
min
|
max
|
min
|
max
|
||
|
Zahn Cups (See ASTM D 4212)
|
|||||
|
1
|
v = 1.1 (t – 29)
|
35
|
80
|
5
|
60
|
|
2
|
v = 3.5 (t – 14)
|
20
|
80
|
20
|
250
|
|
3
|
v = 11.7 (t – 7.5)
|
20
|
80
|
100
|
800
|
|
4
|
v = 14.8 (t – 5)
|
20
|
80
|
200
|
1200
|
|
5
|
v = 23t
|
20
|
80
|
400
|
1800
|
|
Shell Cups (See ASTM D 4212)
|
|||||
|
1
|
v = 0.226 (t – 13)
|
20
|
80
|
2
|
20
|
|
2
|
v = 0.576 (t – 5)
|
20
|
80
|
10
|
50
|
|
2½
|
v = 0.925 (t – 3)
|
20
|
80
|
20
|
80
|
|
3
|
v = 1.51 (t – 2)
|
20
|
80
|
30
|
120
|
|
3½
|
v = 2.17 (t – 1.5)
|
20
|
80
|
40
|
170
|
|
4
|
v = 3.45 (t – 1)
|
20
|
80
|
70
|
270
|
|
5
|
v = 6.5 (t – 1)
|
20
|
80
|
125
|
520
|
|
6
|
v= 16.2 (t – 0.5)
|
20
|
80
|
320
|
1300
|
|
Ford Cups (See ASTM D 1200)
|
|||||
|
1
|
v = 0.49 (t – 35.0)
|
55
|
100
|
10
|
35
|
|
2
|
v = 1.44 (t – 18.0)
|
40
|
100
|
25
|
120
|
|
3
|
v = 2.31 (t – 6.58)
|
20
|
100
|
49
|
220
|
|
4
|
v = 3.85 (t – 4.49)
|
20
|
100
|
70
|
370
|
|
5
|
v = 12.1 (t – 2.00)
|
20
|
100
|
200
|
1200
|
* While the equations in this table are widely used, the equation v = at – b/t is often more applicable, especially at low flow times and low kinematic viscosity.
Copyright - 2025 - Hoskin Scientific
