Rosemount Model 8800C Vortex Flowmeter
E-10
For a given input frequency, you may also determine the current
output. Use the prior example with an input frequency of 275 Hz:
URV= 3600 kg/hr LRV= 0 kg/hr F
in
(Hz) = 275
= 10.48 mA
Therefore, an input frequency of 275.00 Hz represents an output
current of 10.48 mA.
Example 3 (SI units)
Fluid = Natural Gas URV = 10,000 NCMH
Line size = 80 mm LRV= 0 NCMH
Line press. = 1000 kPaG C
20
= C
x
/sp. units factor (from Table E-1)
Temp op. = 10 °C Density(
r
) = 9.07754 kg/cu-mtr (oper)
Viscosity = 0.01 cp
K-factor(compensated) = 10.797 (via HART communicator or AMS)
= 700/{10.797 (.0733811/10.48)}
= 9259.2 NCMH
Therefore, an input frequency of 700.00 Hz represents a flow rate of
9259.2 NCMH in this application.
For a given input frequency, you may also determine the current
output. Use the above example at the 8.0 mA point:
URV= 10000 NCMH LRV= 0 NCMH F
in
(Hz) = 375.00
= 11.94 mA
Therefore, an input frequency of 375.00 Hz represents a current output
of 11.94 mA.
I
FHz
()
KC
16
LRV–
URV LRV–
-----------------------------------------------------------
16
()
ÍÝ
ËÛ
4+=
275 10.715 0.017602
)
0–
(
3600 0–
------------------------------------------------------------------------------
16
()
ÍÝ
ÌÜ
ËÛ
4+
I
FHz
()
KC
20
()
LRV–
URV LRV–
----------------------------------------------------------------
16
()
ÍÝ
ËÛ
4+=
375 10.797 0.0070020
)
0–
·
(
10000 0–
-------------------------------------------------------------------------------
16
()
ÍÝ
ÌÜ
ËÛ
4+
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