11 Basic Measurement
UMFLUXUS_G8V4-6-1EN, 2018-10-10
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If the data logger or the serial interface is activated, the measuring point number has to be entered:
11.5
Defining the Number of Sound Paths
11.6
Transducer Distance
The transducer distance is the distance between the inner edges of the transducers (see section 3.3.
In case of a measurement in diagonal mode on very small pipes, a negative transducer distance is possible.
11.6.1
Fine Adjustment of the Transducer Distance
In case of large deviations, check if the entered parameters are correct or repeat the measurement at a different point on
the pipe.
Repeat the steps for all channels on which a measurement is being made. The measurement will be started automatically.
Enter the measuring point number. Press ENTER.
If arrows are displayed in the lower line on the right, ASCII text can be entered. If no arrows
are displayed, only digits, point and hyphen can be entered.
A value for the number of sound paths corresponding to the connected transducers and the
entered parameters is recommended. Change the value, if necessary. Press ENTER.
For the definition of the sound paths see section 3.3.
A value for the transducer distance is recommended. Fix the transducers (see chapter 8).
Adjust the transducer distance.
Press ENTER.
A
- measuring channel
Reflec
- reflection arrangement
Diagon
- diagonal arrangement
Note!
The accuracy of the recommended transducer distance depends on the accuracy of the entered pipe
and fluid parameters.
If the displayed transducer distance is adjusted, press ENTER.
The measuring for the positioning of the transducers is started.
The amplitude of the received signal is displayed by the bar graph
S=
.
If the LED of the measuring channel lights green, the signal is sufficient for a measurement.
If the LED of the measuring channel lights red, the signal is not sufficient for a measure-
ment.
• Shift a transducer slightly within the range of the recommended transducer distance until
the LED of the measuring channel lights green.
The following quantities can be displayed in the upper line by pressing key
and in the
lower line by pressing key
:
•
■
<>
■
=: transducer distance
• C: ratio of the useful signal and the correlated disturbance signal as a bar graph. If min. 1
box is displayed, the signal is sufficient for the measurement. Three or more boxes are
optimal for a measurement.
•
SCNR
: ratio of the useful signal and the correlated disturbance signal as a numerical val-
ue. If min. 20 dB is displayed, the signal is sufficient for the measurement. A value of 40
dB is optimal for the measurement.
•
time
: transit time of the measuring signal in
μ
s
•
S=
: signal amplitude
•
Q=
: signal quality, bar graph has to have max. length
If the signal is not sufficient for measurement,
Q= UNDEF
will be displayed.
After the precise positioning of the transducers, the recommended transducer distance is
displayed again.
Enter the actual (precise) transducer distance. Press ENTER.
A:Meas.Point No.:
xxx (
↑↓←
→
)
A:
2NUM
A: Sound Path
2
NUM
Transd. Distance
A:53.9 mm Reflec
Transd. Distance
A:
53.9
mm !
S=
■■■■■■
A:
■
< >
■
=53.9 mm!
S=
■■■■■■
Q=
■■■■■■■■■■■■
time=
94.0
μ
s
Q=
■■■■■■■■■■■
Transd. Distance?
54
mm
