Liquid Controls SP3850 - Manual (Page 46)

SP3850 Flow Computer
42
7.2 Flow Equations: (Continued)
Fluid Equations Viscosity Computation:
Liquid Case
Gas Case
cP viscosity = A • (Tf + 459.67) B
Uncompensated Flow Computation:
Pulse Input; Average K-Factor
input frequency • time scale factor
Volume Flow =
K-Factor
Pulse Input; Linear Table
input frequency • time scale factor
Volume Flow =
K-Factor (Hz)
Pulse Input; UVC Table
input frequency • time scale factor
Volume Flow =
K-Factor (Hz/cstk)
Pulse Input; Strouhal/Roshko Table
input frequency • time scale factor
Volume Flow =
Strouhal Cal / (1 + 3 • meter exp coeff. • 1 e-6 (Tf-Tcal)
input frequency • (1 + 2 • meter exp coeff. • 1 e-6 (Tf-Tcal)
Roshko Cal =
cstk
Pulse Input; Stouhal/Roshko Table
input frequency • time scale factor
Corrected Volume Flow Computation:
Liquid Case
Temperature Transmitter
Standard Volume Flow = volume flow • (1 - Therm.Exp.Coef. • (Tf-Tref)) 2
Density Transmitter
density
Standard Volume Flow = volume flow •
reference density
Gas Case
std.volume flow = volume flow • Pf
.
• (T ref
+ 459.67) • Z
ref
.
P
ref
( Tf + 459.67) Zf
Mass Flow Computation:
Mass Flow = volume flow • density
A exp
B
(Deg F + 459.67)
Absolute Density
( )
† centistokes =
Where: centistokes = cP/(kg/l)