EUFM Flow measuring device with air flow meter
Fläkt Woods 4055 GB 03.01 1 Specifications are subject to alteration without notice
EU Air Handling Unit INSTALLATION
Measurement
1. Clean the measuring device whenever necessary (see
”Maintenance” below).
2. Connect the instrument for pressure differential mea-
surement to the pressure tappings of the measuring
device (see under ”Accuracy” below).
3. Read the pressure differential Dp, Pa.
4. Read the air flow q20 m3/s for the relevant unit size
from the pressure differential/flow chart.
Temperature correction
The chart is applicable to air at a temperature of +20° C.
If the air temperature is different, either
– the air temperature must be adjusted to +20° C or
– the air flow must be corrected,
using the expression:
where q = actual air flow and t = actual air temperature.
Accuracy
The accuracy of the measuring device is ± 5% of the
pressure differential reading, provided that
– the measuring tubes and their holes have been
thoroughly cleaned and wiped dry.
– the measuring device is located so that the air flow is
not disturbed by dampers, angle sections or mixing
sections in the ducting.
– the pressure differential is recorded by an instrument
with good accuracy, such as a micro-manometer, Betz
manometer or Magne-Helic direct-reading instrument.
Maintenance of flow measuring device
Clean the measuring tubes by means of a grease solvent,
such as the ULCZ-01 cold degreasing agent, and wipe
dry with a piece of lint-free cloth.
Also check that the air holes are free from dirt.
Filling the manometer
Back off the zeroing screw as far as it will go, and then
screw it in three full turns to enable zero point adjustment
to be carried out in either direction. Remove the filler
screw. Pour the manometer liquid supplied into the filler
hole until the liquid level has risen to the zero point.
N.B. Never use any other type of liquid than that sup-
plied. Carefully adjust the zero point using the
zeroing screw.
Fit the filler screw and tighten it. If the manometer has
been overfilled so that the zero point cannot be set to the
correct position, excess liquid can be removed by inserting
a pipe cleaner or the like into the filler hole. Alternatively,
pour out a little of the liquid.
Connecting the hoses
Cut the 4 mm i.d. hoses supplied to suitable lengths, and
connect them between the tappings on the end wall of the
unit and those on the instrument. Connect plus to plus
and minus to minus. If the unit is equipped with a
silencer, the tappings are located on the inspection side
of the silencer. Clip the hoses in position so that they
will not be damaged or kinked.
(Pa)
-+
0
+
+
+
++
000
0
ms
3
/
/s
m
3
/s
m
3
/s
m
3
/s
m
3
0.20.2
0.2
0.2
0.2 0.30.3
0.3
0.3
0.3 0.40.4
0.4
0.4
0.4 0.60.6
0.6
0.6
0.60.80.8
0.8
0.8
0.8
1.01.0
1.0
1.0
1.0
1.21.2
1.2
1.2
1.2
1.41.4
1.4
1.4
1.4
J4129410-2101
EULF-11
EULF-11
q =
19.86
1 p
m /s
3
MODEL M 700 PA MANOMETER
DWYER INSTRUMENTS, INC.
MICH. CITY IND. 46360 U.S.A.
∆p
Spirit
level
Filler screw
Zeroing screw
Indicating instrument
273 + t
293
q = q20
/