Tabla de contenido
Publicidad
Idiomas disponibles
Idiomas disponibles
9
Calculation of viscosity
The number of seconds stated for the various capillaries in the tables for the kinetic energy
correction (HC) are subtracted from the determined efflux time. Intermediate values may be interpolated.
For absolute measurements, the corrected efflux time multiplied by the constant K gives the kinematic
*
viscosity (mm
2
/s)
) directly.
The viscometer constant K is mentioned in the enclosed production certificate.
10 Example of calculation
Ubbelohde Viscometers Type no. 540 .., 541 .., 542 .., 543 .., 544 ..
Capillary I
Constant
Flow time (averaged)
Kinetic energy correction (HC) for 180,00 s
Kinematic viscosity
*
) previously centistokes [cSt];
For Ubbelohde viscometer from SI Analytics GmbH, the same correction seconds (kinetic energy
correction (HC) apply to identical capillary diameters. A redetermination of the kinetic energy
correction (HC) is not necessary if SI Analytics GmbH viscometers of identical capillary size are replaced.
If requested, the AVS measuring instruments can automatically calculate the kinetic energy
correction (HC) according to the formula on which the tables are based (see the AVS operating
instruction).
11 Measurements and device constants
Ubbelohde viscometers
Type 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
ν = K (t
1 [cSt] =
ISO 3105, DIN 51 562, BS 188 / NFT 60-100
Type no. 540 .., 541 .., 542 .., 543 .., 544 ..
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
ϑ)
–
=0.01000
=180.00
[s]
= 0.30
[s]
ν = K (t
ϑ)
–
–
= 0.01•(180.00
0.30)
=1.797
[mm
2
1
[mm
2
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
6000
to
above 10000
/s]*
/s]
2
/s (cSt)
1.2
3
5
10
30
50
100
300
500
1000
3000
5000
10000
30000
30000
Publicidad
Capítulos
Tabla de contenido
