Talk:Ultrasonic flow meter

Physics: Fluid Dynamics / Acoustics Low‑importance

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Context

The intro should say what it is, what it does, when it is used. NickelShoe 16:38, 14 February 2006 (UTC)[reply]

Multiple problems with this article. Doppler is not a 'recent' developement, as far as I know it is the oldest ultrasonic flowmeter technology and mostly discredited or at least highly unpopular with most knowledgable flowmeter engineers in industrial applications. I cannot speak for their use in medical applications. There are also at least two other ultrasonic flowmeter technologies not mentioned, correlation tag and transflection methods. The line about ultrasonic flowmeters being affected by temperature, viscosity and density is very misleading. There is at least one ultrasonic flowmeter system that is viscosity, temperature and density independent. Inexpensive to use? Another misleading line, ultrasonic flowmeters range in cost from $1000 to >$100,000. Principles section ignores all systems other then transit time.

Why is there a section on doppler systems but not any other? It appears that the article is written or has been edited by someone who either has knowledge of only or bias towards doppler. As someone who has twenty years experience in multiple ultrasonic flowmeter technologies, my opinion is this article is at best highly misleading and uninformed. At worst, it is complete rubbish and should be removed. This is precisely the kind of article that gives wikipedia such a poor reputation as a serious reference. —Preceding unsigned comment added by 83.147.135.60 (talk) 10:43, 9 April 2011 (UTC)[reply]

Cross-pipe transit equation/assumption

I tagged this text with a citation needed:

> Using these two transit times, the distance between receiving and transmitting transducers and the inclination angle , if we assume that sound has to go against the flow when going up and along the flow when returning down[citation needed],

This assumption would make sense for the transducers to be both aiming along the pipe, where one beam opposes the flow and the other follows the flow, but the diagram clearly shows aiming across the pipe, with the plane of the angle between the sensors aligned with the flow. The component of velocity along the beam due to the flow would be rightward in both cases.

The derivation looks wrong with respect to that diagram.

Drf5n (talk) 14:14, 27 September 2024 (UTC)[reply]

Thinking further, the sentence is confusing about "going up" and "going down" -- The diagram shows arrows going from both ends of the probe, One set from the upstream end of the probe, to the reflector and then to the downstream end of the probe. The time to make that journey is t_down. The other set of arrows point from the downstream end of the probe, to the reflector and then to the upstream end of the probe. The time to make that journey is t_up. The "returning" word is confusing, since it isn't supposed to men the return from the reflector to the probe, but perhaps mean an answering ping from the upstream end of the probe to the downstream end of the probe.

The sentence would be more accurate as:

> Using these two transit times, the distance between the transducers and the inclination angle, if we assume that sound has to go against the flow when going upstream and along the flow when going downstream, we can write equations for the upstream and the downstream pings and solve for the speed of sound and the velocity of the flow."

Drf5n (talk) Drf5n (talk) 14:52, 27 September 2024 (UTC)[reply]