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FCO432 Users Guide Issue 1
Using a Laminar Flow Element
The 400 Series Pressure transmitters can be used with any primary element that generates a
differential pressure that is linear. The most common device is the Furness Controls Laminar Flow
Element (LFE). This device will provide a differential pressure that is directly proportional to the
measured flow rate.
Example:
Measuring the air flow through a pipe with a maximum flow of 16 std. l/m. At the measuring point, the
static pressure is 2bar absolute (1bar gauge) and the air temperature is 30°C.
The FCO432 is used with the FCO96-20L LFE (Laminar Flow Element).
The LFE is calibrated to give a Differential Pressure of 104Pa for 20 l/min of air at standard
conditions.
Using the LFE calculation, the Differential Pressure for maximum flow is determined.
gas
std
lfe
lfe
std
fs
fs
std
r
T
T
P
P
Q
P
Q
P
026
.
1
14
.
293
14
.
303
201325
101325
20
104
16
P
43
.
44
P
Pa
Therefore, a Model 2 FCO432 is selected which has a maximum differential pressure range of 150Pa.
The FCO432 needs configuring to measure 0 to 44.4Pa with a display of 0 to 16 l/m.
Set the
Display
mode to
Custom
Set the
Units
to
Pa
Set the
Custom Units
to
l/m
Set
DP Low
to
0.0
Set
DP High
to
44.4
Set the
Decimal Point
to
00.00
Set
Display Low
to
0000
Set
Display High
to
1600
