Thermo Scientific HAAKE Instruction Manual page 29

Appendix
14. Appendix
14.1 Example: Evaluation
(sugar solution of 40 %)
Density of ball 2:
Density of the solution:
Ball constant K :
Falling time:
Measuring temperature:
The absolute viscosity is ...
= 0,09  (2,2 -- 1,18)  61 = 5,60 (mPa  s)

20C
In most cases the densities of the test liquids are known. The
evaluation may be simplified by introducing a factor which
includes the densities. In our example of the sugar solution
the exact factor is ...
( --  )  K = 0,1098 (mPa  s / s)
1 2
14.2 Example: Calibration of ball 1
K = ball constant to be found
= 4.63 [mPas] viscosity of the standard liquid

E
= 2.217 [g/cm ] density of the ball
3

1
= 0.81 [g/cm ] density of the standard liquid
3

2
t = 417.7 [s] average of the falling time
For the calculation of the ball constant K the following for-
mula applies:
η
E
K =
=
(Ã ) ⋅ t
− Ã
1 2
The determination of the constants of the other balls should
be done in the same way.
27
3
2.2 (g/cm )
3
1.18 (g/cm )
0.09 (mPascm
61 s
20.0C
4.63
(2.217 − 0.81) ⋅ 417.7
3
/gs)
= 0.00788