Am Instru Q-FP 201, Руководство пользователя

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INSTRU Q-FP 201
Handheld Ultrasonic Flowmeter
An optimum location would be defined as a straight pipe length full of liquid that is to be measured.
The piping can be in vertical or horizontal position. The following table shows
Piping Configuration
and
Transducer Position
Upstream
Dimension
Downstream
Dimension
Lup
x Diameters
Ldn
x Diameters
L up
----0.--
1 Ldn
—
gm
10D
5D
i
Lup
1 Ldn
1OD 5D
----.—
i
Lup
Ldn
1OD
5D
i
Lup
—
I
Ldn
12D 5D
I
I Q
Lup
Ldn
IM.Eript-,
20D
5D
i
1_,,,,,
_....__
Ldn
.,-,...
20D 5D E><
i
Lup 1 Ldn
30D
5D
1
/
YI
Examples of optimum locations.
Principles to selection of an optimum location
(1) Install the transducers on a longer length of the straight pipe. The longer the better, and make
sure that the pipe is completely full of liquid.
(2) Make sure that the temperature on the location does not exceed the range for the transducers.
Generally speaking, the closer to the room temperature, the better.
(3) Take the pipe fouling into consideration. Select a straight length of a relatively newer pipe. If
the condition is not satisfying, consider the fouling thickness as part of the liner for a better
result.
(4) Some pipes have a kind of plastic liner, and between the outer pipe and the liner there may be a
certain thickness difference that will prevent the ultrasonic waves from direct traveling. Such
conditions will make the measurement very difficult. Whenever possible, try to avoid this kind
of pipes. If impossible, try our plug-in transducers that are installed permanently on the pipe by
drilling holes on the pipe while liquid is running inside.
§2.7 Transducers Installation
The transducers used by the
Q-FP 201
eries ultrasonic flow meter are made of piezoelectric
crystals both for transmitting and receiving ultrasonic signals through the wall of liquid piping
system. The measurement is realized by measuring the traveling time difference of the ultrasonic
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