Emerson Rosemount 8600 Series - Page 22

Reference Manual
00809-0100-4860, Rev BF
Configuration
May 2019
14
Rosemount 8600 Vortex Flow Meter
Density ratio
Used to convert actual volumetric flow to standard volumetric flow rates based on the
following equations:
Calculate density ratio
Calculates the density ratio (shown above) based on user entered process and base
conditions.
Operating conditions
T
f
= absolute temperature at actual (flowing) conditions in degrees Rankine or Kelvin. (The
transmitter will convert from degrees Fahrenheit or degrees Celsius to degrees Rankine or
Kelvin respectively.)
P
f
= absolute pressure at actual (flowing) conditions psia or KPa absolute. (The transmitter
will convert from psi, bar, kg/sqcm, kpa, or mpa to psi or kpa for calculation. Note that
pressure values must be absolute.)
Z
f
= compressibility at actual (flowing) conditions (dimensionless)
Base conditions
T
b
= absolute temperature at standard (base) conditions degrees Rankine or Kelvin. (The
transmitter will convert from degrees Fahrenheit or degrees Celsius to degrees Rankine or
Kelvin respectively.)
P
b
= absolute pressure at standard (base) conditions psia or KPa absolute. (The transmitter
will convert from psi, bar, kg/sqcm, kpa, or mpa to psi or kpa for calculation. Note that pressure
values must be absolute.)
Z
b
= compressibility at standard (base) conditions (dimensionless)
Example:
Configure the Rosemount 8600D to display flow in standard cubic feet per minute (SCFM).
(Fluid is hydrogen flowing at conditions of 170 °F and 100 psia.) Assume base conditions of
59 °F and 14.696 psia.)
FastKeys
1, 3, 2, 4, 1, 1
FastKeys
1, 3, 2, 4, 1, 2
FastKeys
1, 3, 2, 4, 1, 2, 1
FastKeys
1, 3, 2, 4, 1, 2, 2
DensityRatio
density at actual (flowing) conditions
density at s dard (base)tan conditions
--------------------------------------------------------------------------------------------------------=
DensityRatio
T
b
xP
f
xZ
b
T
f
xP
b
xZ
f
---------------------------=
DensityRatio
518.57 °Rx100 psiax1.0006
629.67 °Rx14.7 psiax1.0036
---------------------------------------------------------------------------- 5.586= =