Talk:Gray (unit)

message: Could use some pronunciation text? Is it "g-ray" or just "gray?"
76.226.54.17 (talk) 20:21, 1 December 2013 (UTC)
thread_title: pronunciation

message: I deleted the following recent addition:
"Some users of very large amounts of nuclear radiation - for example, the food irradiation industry - have shifted from rads to grays, since the larger scale of the unit results in a smaller number.   For example, 100,000 rads, an enormous amount of radiation (more than 1,000 times the lethal dose for human beings), can be described as 1 kilogray, or 1kGy, which to the lay audience seems like a smaller amount than a measurement that uses the number 100,000."
Ascribing political motives to a shift to internationally accepted standards seems a bit of a stretch. The food industry could just as well have used the megarad, in which cast the usage cited would be only 1/10 of an Mrad. In any case, this seems inappropriate in an article about the unit. --agr 00:53, 16 September 2005 (UTC)
thread_title: Alleged misuse of the unit

message: The Goiânia accident article data suggests that exposure to even 4+ Grays is often fatal for humans.
Dialectric (talk) 21:24, 19 January 2008 (UTC)
thread_title:  More Details on risk to Humans 

message: In our laboratory we use 1Gy = 0.00876 R, that gives 114.155 instead of 107.185 from article. Since I don't know the calculations leading to this coefficient, I feel I am not the right person to change it in this article. I have a feeling that this is because of the energy used to create an ion pair in the air is 33.9 [eV] and it is usually not equal to the chemical ionisation energy, even if it is called the same thing.
I don't have access to ICRU report 31 which should be source of this value.
Regards,
 213.25.33.100 (talk) 07:16, 13 August 2008 (UTC)
thread_title:  R to Gy conversion 

message: I've checked in a lot of places to see if the Gray unit was actually an SI base unit. But I can't find anything. 
If this isn't actually an SI unit, then the article shouldn't state that it is. I don't know enough about the SI or radiation in general to feel comfortable editing tis article. But could someone please find the truth!
Helixer (talk) 17:05, 5 October 2008 (UTC)
replies: text: it can be fatal because you still absorbed the exact same amount of energy during that one nanosecond.145.120.22.201 (talk) 14:38, 17 February 2012 (UTC)
thread_title:  Really SI base unit? 

message: the article is too much focused on Biological effect, while Gy and rad are unit of absorbed dose by matter, inanimated too.
They are intended to measure the matter damage, but mainly for non biological matter. For biological effect there's Sievert and rem units.--Efa (talk) 16:14, 26 November 2009 (UTC)
thread_title: Biological effect centric

message: Do we really need to repeat the conversion between rads and grays?  This is covered in the first paragraph of the article.  
Also do we really need the table listing all the SI prefixes?  If the reader has a sufficiently sound scientific background to understand the article, then (s)he almost certainly understands the SI prefixes as well.
I suggest that this section be stripped of everything apart from the discussion on röntgens and that the section be renamed "Grays and röntgens". Martinvl (talk) 20:07, 2 February 2010 (UTC)
thread_title: Conversions

message: Where does the "strongly discouraged" quote come from? It is not cited, so it probably shouldn't be there.  —Preceding unsigned comment added by 134.174.21.5 (talk) 19:20, 20 August 2010 (UTC)
replies: text: This has now been clarified by a cut-and-paste job from the rad article. Martinvl (talk) 20:28, 20 August 2010 (UTC)
thread_title:  Intro Quote 

message: A figure I always find interesting in a discussion about the health effects of radiation, which could be of interest to the reader, is this one:
"The total energy absorbed by a 75 kg individual with a whole body exposure of 600 rads (fatal in most cases) is 450 joules. It is interesting to compare this to the kinetic energy of a .45 caliber bullet, which is about 900 joules."
(from http://nuclearweaponarchive.org/Nwfaq/Nfaq5.html but easily calculated)
After some adjustments for context, and taking a smaller bullet, I suggest adding it to the article after the comment about 5 Gy usually being lethal:
The total energy absorbed by a 80 kg individual with a whole body exposure of 5 gray is about 400 joules. It is interesting to compare this to the kinetic energy of a 9 mm bullet, which is about 450 joules."
Thomas Thomasonline (talk) 08:06, 26 September 2010 (UTC)
thread_title:  Energy comparison 

message: There were a couple of citations that originally pointed to books.google.de, with a long untrimmed URL. I switched them to point to books.google.com and trimmed the URL to the minimum using the tool. But now I see that they've been switched back to the books.google.de, and seemingly back to their original length. What's the logic for preferring the german version on english wikipedia, and what's the benefit of the additional URL queries?--Yannick (talk) 03:10, 20 May 2012 (UTC)
replies: text: Hi Yannick - I am currently working in Germany - my office PC seems to pick up the German site. In addition, the office seems to pick up a bigger extract of Lovell's book than does my personal PC, other than than I have no preference as to which site is used. Martinvl (talk) 06:13, 20 May 2012 (UTC)
replies: text: I would guess your laptop has some kind of UK setting because one of your cites uses the google.co.uk site. The different country sites have different missing pages: In Guill, UK is missing page 66-67, DE is missing 67-68, and CA is only missing 65. Linking the COM site should automatically bounce the user to the site in his home country, so it wouldn't change what you see. The extra length in URL queries does things like highlight search terms and force all the buttons, etc. to show up in German regardless of which nation's site you use. I can read enough german to get by, but it would make more sense to link to English on English wikipedia. If I fix the URL's could you try to preserve them in future edits? Thanks.--Yannick (talk) 12:14, 20 May 2012 (UTC)
replies: text: My appologies. Martinvl (talk) 15:35, 20 May 2012 (UTC)
thread_title:  Why must we use the german google site? 

message: Hello,
there is one thing I do not understand about this unit.
Can someone enlighten me?
Gray is defined as absorption of one joule by one kilogram of matter. But I suppose that one kg of lead absorbs more energy that 1 kg of iron when exposed with the same "amount" of radiation. So when I set my X-ray unit to let's say 70 kV, 500 mAs and I expose 1 kg of iron and then 1 kg of lead, it will be a different dose expressed in grays (even when the setting of X-ray device stays the same)?
Or maybe better question - my Unfors measuring unit does show me the dose in grays. But to which matter is this dose calculated? Is it the average human tissue?
Chrabros (talk) 10:22, 30 May 2012 (UTC)
replies: text: The same beam with the same energy fluence will deposit a different absorbed dose in iron than in lead, even when the settings of your X-ray device stays the same. For your Unfors unit, you'll have to read the manual or contact the manufacturer. But from the specs on their ThinX RAD, I would guess it's actually measuring kerma in air, as similar devices from other manufacturers usually do. (Both kerma and absorbed dose are measured can be measured in gray, but only kerma is measured in roentgen. And then their conversion factor tips me off that they're assuming air.) If I'm right, then the absorbed dose to your patient will be about 10% higher than what your instrument says.--Yannick (talk) 13:32, 30 May 2012 (UTC)
thread_title:  Measuring the dose in gray? 

message: Is the plural "gray" or "grays".  I checked the Oxford English Dictionary and they gave two instances of the word "grays" being used, one of which was taken from New Scientist.  I checked the SI brochure. It was silent apart from saying that the normal rules of English grammar are applied.  Does anybody have access to any other authoritative view on the matter? Martinvl (talk) 18:16, 8 May 2013 (UTC)
thread_title:  Plural 

message: Hello fellow Wikipedians,
I have just modified one external link on Gray (unit). Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:
*Added archive https://web.archive.org/web/20121116084754/http://www.icrp.org/publication.asp?id=ICRP+Publication+103 to http://www.icrp.org/publication.asp?id=ICRP+Publication+103
When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.
Cheers.—InternetArchiveBot (Report bug) 12:00, 24 March 2017 (UTC)
thread_title:  External links modified