Talk:International System of Units/Archives/12/2009

Non-break space between numbers and degrees Celsius (°C)
I just removed for the second time a rule for adding a space between the number and the degree symbol for temperatures in Celsius (°C); for example, one would write 12 °C, not 12°C. In Canada, no space is permitted (Canadian Metric Practice Guide). No space is required for the degree symbol (°) when used for angles so one would wonder why one is needed for temperatures. I don't think we should set down a rule that does not apply universally. I think it would be better to be silent on the issue or list by countries which do and which don't require the space. References would be necessary for each country's regulation. Comments? DGERobertson (talk) 01:26, 29 December 2009 (UTC)


 * I have change the article back because no citation has been given for the conflicting Canadian standard. I have also changed "non-breaking space" to "space" because I find nothing in the citations that indicates a non-breaking space. I hope Dger will provide a citation. --Jc3s5h (talk) 16:16, 29 December 2009 (UTC)


 * Here's the reference for no space between numbers and °C: National Standard of Canada. Canadian Metric Practice Guide, CAN/CSA-Z234.1-89, 1989, item 3.6.2. The non-break space is a Wikipedia preference not an SI rule (http://en.wikipedia.org/wiki/Space_(punctuation)#Breaking_and_non-breaking_spaces). Note, many publishers also apply this rule so as not to annoy readers by ending a line with a number and having to look for the units on the next line (especially poor form if the units are at the end of a paragraph). DGERobertson (talk) 19:38, 29 December 2009 (UTC)


 * Apparently the Canadian Metric Practice Guide is from 1989, which is a bit out of date. It would be nice to find something more recent, especially since the BIPM document cited in the article should apply to the whole world. --Jc3s5h (talk) 00:04, 30 December 2009 (UTC)
 * The international standard is ISO/IEC 80000, which is an updated version of ISO 31. I don't have access to either document, but the SI Brochure (8th ed., 2006) explicitly refers to ISO 31 (issued in 1992, ie, after the Canadian document referred to above). It also explicitly treats the issue of the unit symbol for degree Celsius (on page 133):
 * That quotation in itself should be sufficient to resolve the issue as far as this article is concerned. Physchim62 (talk) 01:36, 30 December 2009 (UTC)
 * That quotation in itself should be sufficient to resolve the issue as far as this article is concerned. Physchim62 (talk) 01:36, 30 December 2009 (UTC)