Flexim FLUXUS F502BT, Operating Instruction

Page: 92 / 162

10 Troubleshooting
10.1 Problems with the measurement
FLUXUS F502TE
2020-05-29, UMFLUXUS_F502TEV1-5EN
92
Date and time are wrong, the measured values are deleted when the transmitter is switched off.
The data backup battery has to be replaced if the date and the time are reset or wrong or the measured values are deleted
after the transmitter has been switched off and on again. Send the transmitter to FLEXIM.
An output does not work.
Make sure that the outputs are configured correctly. Check the function of the output. If the output is defective, contact FLEXIM.
10.1 Problems with the measurement
A measurement is not possible because no signal is received. An interrogation point is displayed after the
physical quantity.
• Check whether the entered parameters are correct, especially the outer pipe diameter, the pipe wall thickness and the
sound speed of the fluid. Typical errors: The circumference or the radius was entered instead of the diameter. The inner
pipe diameter was entered instead of the outer pipe diameter.
• Check the number of sound paths.
• Make sure that the recommended transducer distance was adjusted when mounting the transducers.
• Make sure that an appropriate measuring point is selected and the number of sound paths was entered correctly.
• Try to establish a better acoustic contact between the pipe and the transducers.
• Enter a lower value for the number of sound paths. The signal attenuation might be too high due to a high fluid viscosity
or deposits on the inner pipe wall.
The measuring signal is received but no measured values can be obtained.
• An exclamation point ( ! ) in the lower line on the right indicates that the defined upper limit of the flow velocity is exceeded
and, therefore, the measured values are marked as invalid. The limit has to be adapted to the measuring conditions or the
check has to be deactivated.
• If no exclamation point is displayed, a measurement at the selected measuring point is impossible.
The signal is lost during the measurement.
• If there is no measuring signal after the pipe had been run empty and refilled, contact FLEXIM.
• Wait a moment until the acoustic contact is reestablished. The measurement can be interrupted due to a temporarily
higher proportion of gas bubbles and solids in the fluid.
The measured values substantially differ from the expected values.
• Wrong measured values are often caused by wrong parameters. Make sure that the parameters entered for the measuring
point are correct.
10.2 Measuring point selection
• Make sure that the recommended min. distance to any disturbance source is observed.
• Avoid measuring points with deposit formation in the pipe.
• Avoid measuring points in the vicinity of deformations and defects on the pipe as well as welds.
• Make sure the pipe surface at the selected measuring point is even.
• Measure the temperature at the measuring point and make sure that the transducers are suitable for this temperature.
• Make sure that the outer pipe diameter is within the measuring range of the transducers.
• When measuring on a horizontal pipe, the transducers have to be mounted laterally on the pipe.
• The measuring point on a vertically mounted pipe has always to be filled. The fluid should flow upward.
• No gas bubbles should form (even bubble-free fluids can form gas bubbles when the fluid expands, e.g., upstream of
pumps and downstream of great cross-section enlargements).
10.3 Maximum acoustic contact
see section 6.2