Instruction manual

Series 240/241 Instruction Manual Appendix C Fluid Calculations
IM-24-A C-3
Calculations for Liquid
Use this formula to determine the settings for “Goyal-Dorais” selections
and “Other Liquid” selections entered in the Fluid Menu. The liquid cal-
culations were taken from Richard W. Miller, Flow Measurement Engi-
neering Handbook (Second Edition, 1989).
Density
The liquid density is found using the Goyal-Doraiswamy Equation. Goy-
al-Doraiswamy uses the critical compressibility, critical pressure and
critical temperature, along with the molecular weight to find the density.
The equation for specific gravity is:
⎟
⎟
⎠
⎞
⎜
⎜
⎝
⎛
−=
C
f
c
c
c
F
T
T
Z
T
Mwp
G 01102.0
008.0
773.0
The specific gravity can then be converted into density.
Viscosity
The liquid viscosity is found by Andrade's equation. This uses two vis-
cosities at different temperatures to extrapolate the viscosity.
Andrade's equation:
R
L
L
T
B
A
deg
exp= μ
To find A and B
1deg2deg
212deg1deg
)/ln(
RR
RR
L
TT
TT
B
−
=
μ
μ
)/exp(
1deg
1
RL
L
TB
A
μ
=
The temperatures are all in degrees Rankin. Do not believe the subscript
R means they are reduced temperatures.