Talk:Pitot tube

message: External links from Pitot, which now redirects here:
*Pitot Tube -- This one says it all in one diagram. 
*eFunda: Theory of Pitot Static Tubes -- This is more exhaustive. — Preceding unsigned comment added by Mendel (talk • contribs) 00:15, 13 November 2004 (UTC)
thread_title: Untitled

message: I believe these terms are reversed in the description.  WRT the diagram the air is being forced down the ceter tube while the outer tube is only exposed indrectly through the holes just as the description states.  However wouldn't this make the center tube parallel and the outter perpendicular? — Preceding unsigned comment added by Mhenwood (talk • contribs) 01:40, 23 November 2005 (UTC)
replies: text: The face of the openings vs. airflow is what determines whether they are parallel or perpendicular I believe - so the centre tube's opening is perpendicular to the direction of airflow, and the outer tube's opening is parallel to the airflow. Hope that's clear? ZoFreX 23:02, 22 May 2006 (UTC)
replies: text: I think ZoFreX is right, however the context is somewhat ambiguous. I'm intending to give this article a serious overhaul when I get the time. Chrisd87 17:23, 9 July 2006 (UTC)
thread_title:  parallel vs Perpendicular 

message: This section needs to discuss the actual operation of a pitot tube. In my opinion the airplane mishaps belong elsewhere.  — Preceding unsigned comment added by 2601:0:B800:DA:E919:B093:682A:261A (talk) 02:34, 23 March 2014 (UTC)
thread_title:  Operation 

message: I've done a fairly major rewrite to this page, in an attempt to tidy it up and make it more accurate. I hope I've succeeded - this is the first time I've made such a large-scale edit to a wikipedia article. I'm intending to continue in due course and talk more about errors due to attitude and the like, and in time maybe translate the German article and incorporate that. Chrisd87 21:36, 9 July 2006 (UTC)
replies: text: Further to this, the image I have added in place of the previous one is translated from the German Wikipedia article. Work is currently underway to translate the other diagrams from that page for inclusion here. Chrisd87 21:40, 10 July 2006 (UTC)
thread_title:  rewrite 

message: Although the Pitot/pitot tube is named after its inventor, Henri Pitot, predominant common usage is for "pitot tube" to be written in lower case (except at the start of a sentence, of course). This article capitalizes it throughout and recently an editor has gone through the Pitot-static system article to capitalized it throughout there as well. Isn't it Wikipedia policy to use the most common expression? Askari Mark (Talk) 18:38, 11 January 2007 (UTC)
replies: text: My sources all show the worid pitot tube being in lower case.  Including source in FAA documentation.  Is that good enough to assume common use? I have other sources I can consult as well but I feel that they will all show lower case usage. -- Chrislk02 (Chris Kreider) 20:17, 11 January 2007 (UTC)
replies: text: I was just reading an Associated Press article on the Air France 447 disaster and noticed that the author made a good summary of the workings of a pitot tube that appears to have drawn on this article as reference.  Why do I think this?  Because the author capitalized “Pitot” which is rarely found in most sources.  Accordingly, I’m decapitalizing the term here.  Since no contrary comment has appeared here in two and a half years, I’m assuming this is consensus.  If not, please address the issue here before reverting.  Askari Mark (Talk) 20:24, 6 June 2009 (UTC)
replies: text: Unnecessary capitalization of the word "pitot" has crept in over the past decades, notably in captions for images. I will change these instances to lower case. Dolphin (t) 00:33, 15 November 2018 (UTC)
replies: text: This is not "unnecessary" capitalization. This is following good grammar. Pitot is a proper noun and should be capitalized. Is the "Joule-Thomson effect" unnecessary capitalization? It is acknowleged that the FAA has made the same error over and over again by dropping the cpaitalzation. However, if you read all text from its Eiuropemna counterpar, EASA, it is corretcly written as Pitot tube, in their standards and other associated publications, therefore official regulatory text. 104.158.159.149 (talk) 14:30, 6 July 2022 (UTC)
replies: text: That proves nothing except that you agree with EASA's usage and disagree with the FAA's. What matters here is usage across a broad range of English language sources, which seem to favor no capitalization. Remember, the EASA represents mostly non-English speaking countries, so may reflect non-English usage in its publishings. BilCat (talk) 01:42, 7 July 2022 (UTC)
thread_title:  Pitot vs. pitot 

message: I am working on a semi re-write/expansion of this article, as well as work on the article on Henri Pitot.  I am using this as kind of a staging area for sources I find related to this/these topics.  If you find any good reliable ones, feel free to add them! Thanks -- Chrislk02 (Chris Kreider) 20:22, 11 January 2007 (UTC)
thread_title:  External Sources 

message: Boats use pitot tubes to measure water speed, but this page makes no mention of that. -- Mikeblas (talk) 02:23, 15 June 2008 (UTC)
thread_title: Marine use

message: Pitot tubes on airplanes are a specific use and should not take over the body of the article.  Aircraft should not be mentioned at all in the definition of pitot tube.  The use of pitot tubes in aviation can be described in a number of other places.  Perhaps in a seperate stub or even as another section in the pitot tube article called something like "common uses" or "in industry".
Understand that saying "A Pitot (pronounced /ˈpiːtoʊ/) tube is a pressure measurement instrument used to measure fluid flow velocity, and more specifically, used to determine the airspeed of an aircraft.", is a lot like saying "A mirror reflects images, and more specifically, used to determine what is behind your car."
When I came across this article I was expecting to see information more like what is contained on the Dwyer website: http://www.dwyer-inst.com/HTDOCS/airvelocity/AirVelocityIntroduction.cfm
Forgive me for not being more constructive; I am just learning to wiki.Steveandaugie (talk) 15:48, 24 June 2008 (UTC)
thread_title:  Specific Use 

message: The author uses stagnation pressure and total pressure interchangably. This is incorrect and misleading. The author should explain that the stagnation pressure is equal to the total pressure only when the velocity of the fluid equals zero and therefore they are not one in the same. Also, Bernoulli's Equation states the total pressure, not the stagnation pressure, is equal to the dynamic plus the static pressure. See Crowe C, Elger D, and Roberson HJ. Engineering Fluid Mechanics. 7th Ed. Wiley. . 142.176.6.109 (talk) 19:23, 1 October 2010 (UTC)
replies: text: I heartily agree with you!  Unfortunately, Wikipedia has a comprehensive article on Stagnation pressure but no such article on Total pressure.  There are articles where the two concepts are treated as synonymous – for example, see the second sentence HERE. I can recall some occasions where I wrote about total pressure but someone came along later and converted it to stagnation pressure so they could make it into a Wikilink to Stagnation pressure.  I thought I was the only one here who saw a significant difference between the two, so I am glad to see there is at least one other! Dolphin (t) 04:15, 2 October 2010 (UTC)
thread_title:  Stagnation vs Total Pressure  

message: I guess there should be some correctional work done on this topic.
Please consult the following article for the idea about the reason for corrections (I don't know if it can be used as a valid source):
http://www.popularmechanics.com/technology/aviation/crashes/what-really-happened-aboard-air-france-447-6611877-2
Regards!  — Preceding unsigned comment added by Dmilojevic (talk • contribs) 14:23, 9 December 2011 (UTC)
replies: text: Yeah, that's a good summary article, based on a translation of the cockpit conversation in "Erreurs de Pilotage" by Otelli.  The sentence about the connection to AF447 in this article should be removed entirely.  See my reply at Air France 447 above. Mathglot (talk) 06:59, 25 June 2013 (UTC)
thread_title:  Assumptions about responsibility for Flight 447 crash 

message: Pitot tube is the term generally used in English for the airspeed measuring instrument found in aircraft.  A rarer form is Pitot probe.  Both expressions are translations from the French. 
The Pitot tube is named after the French invention by engineer Henri Pitot, called a :fr:Tube de Pitot, which translates word-for-word very literally into the English name (not always the case for many inventions).  In French, you also occasionally see the term Sonde de Pitot, which literally translates as Pitot probe, but this is 50 times rarer. On English-language sites, the expression Pitot probe version exists but is even rarer than in French.
On the English wiki, Pitot probe redirects to Pitot tube as of this date; on the French wiki, :fr:Probe de Pitot does not exist.
The situation may be somewhat muddled by the fact that among several companies offering a combination instrument measuring both airspeed and AoA,  at least one (Dynon) calls it a "Pitot probe".  (Side note:  although AoA meters have been available for 50 years, they are not required and often not included as standard equipment on commercial aircraft, but only as an option.  C.B. "Sully" Sullenberger claimed that the lack of an AoA on the Airbus A330 was partially responsible for the confusion of the pilots leading to the crash of Air France 447 in 2009 and The Daily Telegraph reached a similar conclusion.) Mathglot (talk) 07:10, 25 June 2013 (UTC)
replies: text: At least some occurrences of "Probe" are probably due to imperfect translation from French to English by a non-native speaker. An example of "Pitot probe" in English can be seen in this Air France press release containing both English and Portuguese text concerning the investigations of the AF447 disaster (as quoted in the AF 447 article). The English translation is very good, but not perfect, and a bilingual speaker (en-fr) can detect very minor problems in the English that don't affect understanding, but that do indicate that a non-native speaker, or a non-aeronautics expert (or both) was responsible for the English.  In this case, the references to "Pitot probe" (or just "probe") cannot be relied on as authoritative. Mathglot (talk) 23:16, 25 June 2013 (UTC)
thread_title:  Tube or Probe? 

message: Aircraft is possibly the most important application of pitot tubes there is. Since we do have an article specifically describing the systems used on aircraft (pitot-static), we clearly should summarize it here with a main article link. Oiyarbepsy (talk) 13:21, 25 August 2016 (UTC)
replies: text: I agree Aircraft are possibly the most important application of pitot tubes, and I support a prominent link to Pitot-static system. I've no objection to heading that section "Aircraft" and providing a  link to the article. However, I think readers are done a disservice by the wholesale copy-and-pasting of the article lede into this article, some of which is irrelevant to this article. Please note the version you copied from also contained some problematic material which I removed from the main article earlier. Burninthruthesky (talk) 14:17, 25 August 2016 (UTC)

text: The pitot tube is used to measure the local flow velocity at a given point in the flow stream and not the average flow velocity in the pipe or conduit. Errors induced due to the location of the measuring tube on the aircraft, and the effect of localised airflow upon it, are known as "position errors" and need to be factored into resultant calculations.
This information is incorrect on at least three points:
# A flow velocity cannot be measured using a pitot tube. Velocity measurement requires extra information from a static port; or a combined pitot-static tube.
# The local flow velocity at a given point is measured by locating a static port at that given point. Bernoulli's principle tells us that pitot pressure is uniform throughout the flow field, so regardless of where a pitot tube is located, it will supply the same pressure (equal to the total pressure; aka stagnation pressure)
# Pitot pressure is vulnerable to error in the alignment of the pitot tube, but it is not vulnerable to position error. Position error affects the static pressure because the pressure supplied from any static port is highly sensitive to the flow velocity in the immediate vicinity of the port. In contrast, a pitot tube supplies stagnation pressure and so is insensitive to the flow velocity in the immediate vicinity of the pitot tube. Bernoulli's principle can be stated as "stagnation pressure is equal to total pressure which is uniform throughout the flow field".
The source cited for this information is Transport processes and separation process principles by Geankoplis. I don't have access to this book, but either it is incorrect or it has been cited incorrectly. It is not an aviation book, so it is likely that it has been misinterpreted or paraphrased on matters of airspeed measurement and position error.
I will erase these two sentences. Dolphin (t) 01:15, 15 November 2018 (UTC)
thread_title:  Aircraft