Talk:Mercury pressure gauge

A fact from Mercury pressure gauge appeared on Wikipedia's Main Page in the Did you know column on 16 September 2020 (check views). The text of the entry was as follows:

Did you know... that mercury pressure gauges as tall as 23 metres (75 ft) have been built to measure very high pressures?

A record of the entry may be seen at Wikipedia:Recent additions/2020/September. The nomination discussion and review may be seen at Template:Did you know nominations/Mercury pressure gauge.

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Did you know nomination

The following is an archived discussion of the DYK nomination of the article below. Please do not modify this page. Subsequent comments should be made on the appropriate discussion page (such as this nomination's talk page, the article's talk page or Wikipedia talk:Did you know), unless there is consensus to re-open the discussion at this page. No further edits should be made to this page.

The result was: promoted by Cwmhiraeth (talk) 06:21, 12 September 2020 (UTC)[reply]

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... that mercury pressure gauges as tall as 23 metres have been built to measure very high pressures? Source: Hála et al., p. 220

Reviewed: Night Patrol

Created by Spinningspark (talk). Self-nominated at 16:18, 28 August 2020 (UTC).[reply]

General: Article is new enough and long enough
New enough: Long enough:

Policy: Article is sourced, neutral, and free of copyright problems
Adequate sourcing: Neutral: Free of copyright violations, plagiarism, and close paraphrasing:

Hook eligibility:

Cited: - I looked at page 220 of the source on Google Books, and it doesn't seem to mention that the high mercury columns were 23 m tall. [1]
Interesting:

QPQ: Done.

Overall: The hook is interesting, the article is long enough and new enough (was created less than five hours ago [2]), but as I mentioned above, it doesn't look like "23 m" specifically is mentioned in the book. Was there another source that verified this statistic? Mz7 (talk) 18:18, 28 August 2020 (UTC)[reply]

@Mz7: The source gives the pressure range in standard atmospheres. There is a straightforward conversion between standard atmospheres and miilimetres of mercury. This is so well known and frequently used that the {{convert}} template will output this result (and is used in the article). I maintain that this is a case where WP:CALC can be invoked, but a source for the conversion factor is easily found if required. SpinningSpark 18:52, 28 August 2020 (UTC)[reply]

@Spinningspark: Ah, I see. It has been many moons since I was exposed to these kinds of conversions, and after further review, I believe you are right. Good to go, in that case. Mz7 (talk) 19:07, 28 August 2020 (UTC)[reply]

Please add an inline cite for the hook fact per WP:DYK#Cited hook 3. Thank you, Yoninah (talk) 20:57, 6 September 2020 (UTC)[reply]

Yoninah, what exactly is the problem? The article states;

Gauges for measuring pressure in the range 20–30 standard atmospheres (15,000–23,000 mmHg) have been built.

and that is directly cited to Hála et al., p. 220. The source says

High mercury columns, which in principle in no way differ from normal manometric U-tubes, are used as an absolute standard for measuring pressures from 20 to 30 atm.

Why is that not good enough? SpinningSpark 11:28, 7 September 2020 (UTC)[reply]

Sorry, I was looking at the 23m number in the next sentence and didn't see a cite. But now I see that 23,000mm is indeed 23m. Restoring tick. Yoninah (talk) 12:04, 7 September 2020 (UTC)[reply]

Thanks Yoninah. Ironically, I originally wrote 23 m manually, but when I nominated it for DYK I changed it to go through the {{convert}} template to show I wasn't just making stuff up. The template can only do mm or inches, not metres, so perhaps another case of templates are evil perhaps. This source (not used in article) directly gives a maximum figure in metres (30 m) for high-pressure mercury gauges but doesn't say what has actually been built. SpinningSpark 12:55, 7 September 2020 (UTC)[reply]