Emerson Rosemount 8600 Series Reference Manual page 22

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