[Tagging] Feature Proposal - RFC - temperature
sommerluk at gmail.com
Thu Feb 5 07:50:35 UTC 2015
If we look how other units are treated in OSM
(http://wiki.openstreetmap.org/wiki/Map_Features/Units) than the keys
have always default units. Which one is the default unit differs from
key to key. For example, the default unit for width=* is “meter”,
while the default unit for distance=* is “km”. So the default unit is
not based on SI units, but on the commonly used unit for this
I suppose that in most countries of the world, °C is the common unit
for temperature in daily normal live. °F is only used in very few
countries. °K is only used in the scientific world, but not in daily
So I think it’s important to have a clearly defined default unit, and
this default unit should be °C. Nevertheless, I think it is a good
idea to encourage people to tag “with” the unit.
2015-02-05 0:53 GMT+00:00 Dave Swarthout <daveswarthout at gmail.com>:
> For clarification, the Kelvin temperature scale is almost never used outside
> of a chemistry or physics lab. Absolute zero, the lowest possible
> temperature, is defined as 0 degrees Kelvin. That is approximately equal to
> minus 272 C and minus 460 F. Nobody working on OSM is likely to be
> specifying temperatures in degrees K.
> <begin rant>
> I also think Americans, and I am one, need to get over the use of degrees F
> and the old inch/foot/mile system. It's stupid and anachronistic to base the
> units of length on the length of "the king's thumb", or whatever. Continuing
> to make exceptions for them is only perpetuating their intransigence.
> <end rant>
> This specification is getting quite complex, don't you think? I'm betting we
> will never see most of these fine gradations in temperature rendered on a
> my 2 cents
> On Thu, Feb 5, 2015 at 4:05 AM, Warin <61sundowner at gmail.com> wrote:
>> On 5/02/2015 1:02 AM, fly wrote:
>> Am 04.02.2015 um 10:56 schrieb Kotya Karapetyan:
>> > 1) I would discourage specification of the temperature without the
>> > scale indication. I have never lived in the US but I see from the Web
>> > that Americans like specifying temperature in degrees Fahrenheit
>> > without mentioning it (the same way as we in Europe use centigrade
>> > without underlying it). Taking into account the international nature
>> > of the OSM community, I foresee a significant risk that the map will
>> > get populated with invalid values. Warin is right about SI units, but
>> > SI is not even strictly followed in the technical and scientific
>> > community, not to mention the general public. Obviously, Americans in
>> > general ignore it by using inches, miles and degrees Fahrenheit :) I
>> > am afraid many people will not have heard about SI guidelines and will
>> > not have read the wiki page in significant detail.
>> > Therefore, for the sake of clarity, I suggest always specifying "F" or
>> > "C" with the temperature value.
>> Units for temperature are really wired and obviously Kelvin which I
>> would suspect to be the default is not really used in real live as
>> Celsius has the better scale for real life usage.
>> Matter of common use between C and K.
>> The default of height is metres .. not feet. Don't know if there is any
>> confusion over that? I do take your point over the default.. insisting on
>> the unit may be a good way of ensureing that F is not confused with C. But
>> I'd like to see other people ideas on this .. are they prepared to enter the
>> unit (even thought it is abbreviated) every time they enter a temperature?
>> > 2) I suggest clarifying the verbal specification of the temperature.
>> > - Replace "chilled" with "cool" (by analogy with "warm") and also
>> > because "chilled" actually assumes that I know that the object was
>> > purportedly cooled down, which adds yet another uncertainty and is
>> > usually not very relevant;
>> > - remove the definition of "substantially colder" etc., because it
>> > doesn't add any clarity. I agree that it is important to distinguish
>> > between safe and unsafe situations, so let's just do that:
>> > freezing
>> > cold — may be unsafe to handle
>> > cool
>> > warm
>> > hot — may be unsafe to handle
>> > boiling
>> > adjustable — the object temperature can be changed by consumer/user
>> > variable — the object temperature can vary on its own
>> > ambient — the object always remains at ambient temperature (note that
>> > this may include the object being "cold" and "warm", including being
>> > unsafe to handle, depending on the ambient temperature; think about
>> > water in Siberia rivers in January)
>> Only two values I could live with are cold and hot. Generally these
>> values are too ambiguous and an estimated value is much better.
>> Chilled as in chilled water is in common use. The mapper may want to
>> include it. I don't know how to render that to a map. What a mapper chooses
>> to enter is up to them. I'm only rendering adjustable, hot and cold at this
>> point anyway.
>> > 3) For the numeric specification, I suggest adding:
>> > - "above"/"below" options
>> > - "approximate" value
>> > - range of temperatures (using above/below)
>> > E.g.
>> > temperature:circa = 80 C
>> > temperature:above[:circa] = 300 C
>> > temperature:below[:circa] = 1000 C
>> I would add this in the value like:
>> temperature = < 10 C
>> temperature = > 300 C
>> We still can use source:temperature=estimated
>> No .. you'd have a conflict e.g.
>> temperature = 45
>> temperature = estimated
>> ? which 'value' is 'correct' '
>> Might be better as
>> temperature = 45
>> temperature:accuracy = estimated
>> 4) How do we tag a shower with cold and hot water ?
>> temperature=4 C;80 C ?
>> Does this depend on the hose, e.g. one separate for each temperature or
>> a mix-batterie ?
>> temperature=adjustable .. that is what it is for ... may be an e.g. after
>> the description?
>> Tagging mailing list
>> Tagging at openstreetmap.org
> Dave Swarthout
> Homer, Alaska
> Chiang Mai, Thailand
> Travel Blog at http://dswarthout.blogspot.com
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