Ultrasonic flow meter
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Today I encountered an ultrasonic flow meter; the signal quality at the site was quite good, around 90. The theoretical transmission time was 103, which is also very good. However, the flow meter showed values of –0.5 to –1 m³/h, with a flow velocity of –0.05 m/s. The people on site said that the flow rate should be at least 4 to 6 m³/h. Has anyone encountered this situation before? How to solve it? Can’t ultrasonic flowmeters be used for such low-flow measurements?
Is it installed backwards? There is still interference from strong magnetic fields and motor magnetic fields at the site.
To be honest, from Siemens to Thermo Fisher, I’ve seen very few ultrasonic flowmeters that are used effectively. If it is desalinated water or something similar, electromagnetic methods cannot be used. Then choose domestic swirl-type ones or foreign vortex street types.
The full-scale flow rate of ultrasonic flow meters can be selected within the range of 0.5–12 m/s for the flow velocity of the medium being measured. When the flow velocity in the pipe is too low to meet the requirements of the flow meter, or when accurate measurement cannot be ensured at such a velocity, it is necessary to reduce the diameter of the meter in order to increase the flow velocity inside the pipe and obtain satisfactory measurement results. For integrated types, the main considerations are flow rate, whether the medium is clean, and the presence of bubbles or impurities. For split-type systems, it is necessary to consider whether the calculation spacing is correct, as well as the wall thickness and material of the pipes, their diameter, flow velocity, and whether the fluid is clean or contains bubbles and impurities. It is also important that there is sufficient coupling agent between the sensor’s working surface and the pipe wall, with no air or solid particles present to ensure good coupling. The installation method is a key factor to take into account.