Ahlborn ALMEMO 2290-2/3, Руководство по эксплуатации

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7.1.6 Volume Flow Measurement
For determining the volume flow in VF in ventilating channels the average flow
velocity is multiplied with the cross section area CS:
v
VF =
.
CS
.
0.36 VF = m
3
/h, = m/s, CS = cm
2
v
v
The average flow velocity can be determined by a time-based averaging
v
with rough air volume measurements at air vents (see 7.1.5 and man. 3.5.5).
The rotating vane is properly placed at one end and the averaging is started.
The whole cross section is uniformly measured and, when reaching the other
end, the averaging is stopped again.
Alternatively, the average flow velocity can be determined by
single net
measurements according to VDI/VDE 2640 (see 7.1.5 and man. 3.5.5) (e.g.
13.24 m/s).
Function AVERAGE VALUE ´
AV
´
Select by using the key
F1...
Display m/s:
v
Entering the Cross Section Area
The cross section area CS can either be directly entered within the function
CS, with 32000cm
2
at maximum, or within the function DN via the diameter,
with 2000mm at maximum (see 5.4).
Function CROSS SECTION AREA ´
CS
´
Select by using the key F2... Input cm 2 , see 5.4
Function DIAMETER ´
DN
´
Select by using the key
F2...
Input mm, see 5.4
Indication of the Volume Flow
The result of the multiplication of the average velocity and the cross section
area CS is the air volume. This volume flow VF
is automatically calculated and
is displayed in m
3
/h in function ´
VF
´.
Function VOLUME FLOW ´
VF
´:
Select by using the key
F1...
Display VF m
3
/h:
1: 1 3.2 4
AV
1: 0 1 7 5
.
CS
1: 0 1 5 0
.
D N
1: 0 8 3 4
.
V F
32 ALMEMO

2290-2/3
Continuous Measurement of a Measuring Point