9 Measurement
9.3 Start of the measurement
FLUXUS G809
2020-06-25, UMFLUXUS_G809V2-2EN
104
Consistency check
If a wide range for the sound speed has been entered in the program branch
Parameter
or the exact parameters of the
fluid are unknown, a consistency check is recommended.
The transducer distance can be displayed during the measurement by scrolling the key
.
The optimum transducer distance is displayed in brackets (here: 50.0 mm) in the upper line, followed by the entered trans
-
ducer distance (here: 54.0 mm). The latter value has to correspond to the adjusted transducer distance.
• Press ENTER to optimize the transducer distance.
The optimum transducer distance is calculated on the basis of the measured sound speed. It is therefore a better approx
-
imation than the first recommended value which had been calculated on the basis of the sound speed range entered in the
program branch
Parameter
.
If the difference between the optimum and entered transducer distance is less than specified in Tab. 9.4, the measure
-
ment is consistent and the measured values are valid. The measurement can be continued.
• If the difference is greater, adjust the transducer distance to the displayed optimum value.
• Afterwards, check the signal quality and the signal amplitude bar graph.
• Press ENTER.
Repeat the steps for all channels on which a measurement is made.
Tab. 9.4: Standard values for signal optimization
transducer frequency
(3rd character of the technical type)
max. difference between the optimum and the entered transducer distance [mm]
shear wave transducer
Lamb wave transducer
F
-
-60…+120
G
20
-45…+90
H
-
-30…+60
K
15
-20…+40
M
10
-10…+20
P
8
-5…+10
Q
6
-3…+5
S
3
-
Notice!
If the transducer distance is changed during the measurement, the consistency check has to be repeated once again.
L=(50.0) 54.0 mm
54.5
m3/h
