[Tagging] Straw pole Temperature=objective default unit?

[Warin]

On 10/04/2015 4:50 AM, Andy Mabbett wrote:
> On 9 April 2015 at 01:52, Warin <61sundowner at gmail.com> wrote:
>
>> Say a mapper tags
>>
>> temperature=42
> Under what circumstances would such a tag be used. How would we know
> that the actual temperature is not 41 or 43?
>

You want more detail?

Say a mapper tags
amenity=swimingpool
temperature=42

---------------- Is that enough detail?

The question is
is the 42 taken as degrees Celsius or rejected as an error????

Presently 'degrees Celsius' is a little ahead of ' rejection' .

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Accuracy? really? in OSM? No dimension entry into OSM includes any 
statement of accuracy ...
If you want a full statement of 'accuracy' it would have to be a 
statement of uncertainty with level of confidence and coverage factor.

No .. you don't want to go there!!!!!!
No measurement is 'error free'. They all have some uncertainty ..
Reference http://kcdb.bipm.org/appendixC/search.asp?service=All
For example NIST claim, in thermometry, for a liquid in glass 
thermometer at 'normal' temperatures their best uncertainty is 0.02 K 
(neglecting any contribution by the thermometer being calibrated).

Note : BIPM uncertainties are adjusted for 95% level of confidence and 
approximately a coverage factor of 2.

No .. you don't want to go to statements of errors and accuracy ..

Instead .. what would a 'reasonable person' expect for such a statement 
of 'the temperature is 42 °C'? Most would readily accept ±1°C given the 
resolution of the statement. They may even accept ±2°C .. but not ±10°C.

What would be acceptable for a statement of 'width is 1 metre' given in 
OSM on a path? Why am I wasting time on such a question? Because Andy 
asked. Suggest you do some research on it Andy.