Calculation Of Viscosity; Example Of Calculation - SCHOTT Instruments 567 Mode D'emploi

10 Calculation of viscosity

The number of seconds stated for the various capillaries in the tables of the kinetic energy correction (HC)
are subtracted from the determined efflux time. Intermediate values may be interpolated.
For absolute measurements, the corrected flow time multiplied by the viscometer constant K gives the
kinematic viscosity [mm 2 /s] *) directly.
The viscometer constant K is mentioned in the enclosed production certificate.

11 Example of calculation

Ubbelohde viscometers Ref. No. 501 10
Capillary I
Constant
Flow time (averaged)
Kinetic energy correction (HC) for 180.00 s
Kinematic viscosity
*
) previously centistokes [cSt];
12 Measurements and device constants
Ubbelohde viscometers ISO 3105 / DIN 51 562 / Part 1 / BS 188 / NFT 60-100
Ref. No. Capillary No.
... 00 0
... 03 0c
... 01 0a
... 10 I
... 13 Ic
... 11 Ia
... 20 II
... 23 IIc
... 21 IIa
... 30 III
... 33 IIIc
... 31 IIIa
... 40 IV
... 43 IVc
... 41 IVa
... 50 V
*
) previously centistokes [cSt]; 1 [cSt] = 1 [mm
M = K (t — y)
1 [cSt] =
Ref. No. 501 ... 530 ... 532 ..
Capillary Constant K
∅
(approx.)
(mm)
i
0.36 0.001
0.46 0.003
0.53 0.005
0.63 0.01
0.84 0.03
0.95 0.05
1.13 0.1
1.50 0.3
1.69 0.5
2.01 1
2.65 3
3.00 5
3.60 10
4.70 30
5.34 50
6.40 100
2 /s]
14
=0.01000
=180.00 [s]
y = 0.30 [s]
–
m = K (t y)
–
= 0.01•(180.00 0.30)
=1.797 [mm 2 /s]*
1 [mm 2 /s]
Measuring range mm
(approx.)
0.2 to
0.5 to
0.8 to
1.2 to
3 to
5 to
10 to
30 to
50 to
100 to
300 to
500 to
1000 to
3000 to
above 10000
above 10000
2
/s (cSt)
1.2
3
5
10
30
50
100
300
500
1000
3000
5000
10000
30000