Flexim FLUXUS F502BT, Operating Instruction

Page: 26 / 162

6 Mounting
6.2 Transducers
FLUXUS F502TE
2020-05-29, UMFLUXUS_F502TEV1-5EN
26
6 Mounting
6.2 Transducers
6.2.1 Preparation
6.2.1.1 Measuring point selection
The correct selection of the measuring point is crucial for achieving reliable measurement results and a high measurement
accuracy.
A measurement on a pipe is possible if:
• the ultrasound propagates with a sufficiently high amplitude
• the flow profile is fully developed
The correct selection of the measuring point and the correct transducer positioning guarantee that the sound signal will be
received under optimum conditions and evaluated correctly.
Because of the variety of applications and the different factors that influence the measurement, there is no standard solution
for the transducer positioning.
The measurement is influenced by the following factors:
– diameter, material, lining, wall thickness and shape of the pipe
– fluid
– gas bubbles in the fluid
• Avoid measuring points in the vicinity of distorted or defective areas of the pipe or in the vicinity of welds.
• Avoid measuring points with deposit formation in the pipe.
• Make sure the pipe surface at the selected measuring point is even.
• Select the location of the transmitter within the transducer cable range.
• The ambient temperature at the measuring point has to be within the operating temperature range of the transmitter and
the transducers (see technical specification).
6.2.1.2 Pipe preparation
Rust, paint or deposits on the pipe absorb the sound signal. A good acoustic contact between the pipe and the transducers is
obtained as follows:
• Clean the pipe at the selected measuring point.
– If present, the paint layer has to be smoothed by grinding. The paint does not need to be removed completely.
– Remove rust or loose paint.
• Use coupling foil or apply a bead of coupling compound along the center line of the contact surface of the transducers.
• Observe that there must be no air pockets between the transducer contact surface and the pipe wall.
Caution!
Contact with grinding dust
This may result in injuries (e.g., breathing difficulties, skin reactions, eye irritations).
→ Wear the required personal protective equipment.
→ Observe the applicable rules.
Important!
The pipe has to be sufficiently stable to withstand the pressure exerted by the transducers and the tension straps.
Notice!
Observe the selection criteria of pipe and measuring point.