Emerson Rosemount 8800D Series Reference Manual page 179

Electronics Verification
May 2016
Example 3 (English units)
Fluid
Line size
Line pressure
Operating
Temperature
Viscosity
K-factor
(compensated)
Q
Therefore, an input frequency of 700 Hz represents a flow rate of 5569.4 SCFM in this
application.
For a given input frequency, you may also determine the electrical current output. Use the
above example with an input frequency of 200 Hz.
URV= 5833 SCFM
I = 8.36 mA
Therefore, an input frequency of 200 Hz represents an electrical current output of 8.36 mA.
Electronics Verification
= Natural gas
= 3 inch
= 140 psig
= 50 °F
= 0.01 cp
= 10.678 pulses/gallon (via Field Communicator or AMS Device Manager)
= F/(K x C ) where: C
20
= 700/{10.797 x (0.124675/10.71)}
= 5569.4 SCFM

(
⁄ ×
F K C

I
=
---------------------------------------------------- -

URV LRV

⁄ (
200 10.797 0.011641

I
= -----------------------------------------------------------------------------

5833 0
URV = 5833 SCFM
= 0 SCFM
LRV
C = C /sp. units factor (from
20 x
ρ
Density ( ) = 0.549 lb/cu-ft (operating)
Input = 700 Hz
Frequency
= C /10.71 (Density Ratio)
20 12
LRV= 0 SCFM

) LRV
–
× ( )

20 16 4
+

–
× ) 0
–
×
(
–
Reference Manual
00809-0100-4004, Rev DC
Table C-1 on page168)
F = 200 Hz
in


)
16 4
+

171