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Re: Operating temperatures

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On 10/26/2025 3:06 AM, Chris Jones wrote:
> On 25/10/2025 12:58 am, Don Y wrote:
>> Having to deal with formally specifying operating temperatures
>> of my devices, I've started canvassing other products that are
>> typically installed and/or operated outdoors.
>>
>> Disturbing to see many *proud* to claim 40C!  Our ambient outdoor
>> temperature is in that range for about 1/6 of the year!  And, from
>> *reports* of recent weather and climate patterns, it seems like
>> much of the continental US will find itself in this boat, sooner
>> or later.
> 
> The weather report usually would give the air temperature in the shade.

Yes.  More importantly, it typically gives the temperature somewhere *else*
(e.g., "at the airport" -- I don't know many folks who live THERE!)

A common experiment, here, is to stand in the shade and extend your arm
out into the sunlit area.  With your eyes closed, you can "draw" the line
that the shadow casts on your arm as the difference is very noticeable.

> If your device is installed over a dark road, the air may be quite a bit 
> hotter, but a bigger effect is that if your device is expoed to sunlight, its 
> surfaces may become much hotter than the surrounding air.

Road temperatures are typically 160F.  People frequently visit the hospital
having suffered burns from that surface (if you run out to grab the mail
in bare feet, you learn to move pretty fast!).  I've always wondered how the
outdoor air sensor in the car isn't easily confused!

Likewise if installed in a space that can trap/accumulate heat.  Or, reflect heat.

E.g., many of my cameras are outdoor "hiding" under overhangs soas not to
unduly expose them to the weather; other devices are "in the ceiling" (no
attic, here) where the surface directly above (a few inches) is being baked
by the sun; in the garage (ours is insulated so doesn't get as hot as folks'
who don't have that added barrier; often up near the ceiling; etc.

And, trying to reliably *sense* outdoor temperature is a challenge (as is
tracking the position of the sun).

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Operating temperatures Don Y <blockedofcourse@foo.invalid> - 2025-10-24 06:58 -0700
  Re: Operating temperatures Martin Brown <'''newspam'''@nonad.co.uk> - 2025-10-24 15:56 +0100
    Re: Operating temperatures john larkin <jl@glen--canyon.com> - 2025-10-24 08:12 -0700
    Re: Operating temperatures Don Y <blockedofcourse@foo.invalid> - 2025-10-24 11:16 -0700
      Re: Operating temperatures John R Walliker <jrwalliker@gmail.com> - 2025-10-24 23:57 +0100
        Re: Operating temperatures Don Y <blockedofcourse@foo.invalid> - 2025-10-24 17:18 -0700
          Re: Operating temperatures KevinJ93 <kevin_es@whitedigs.com> - 2025-10-25 11:23 -0700
            Re: Operating temperatures Don Y <blockedofcourse@foo.invalid> - 2025-10-25 12:27 -0700
          Re: Operating temperatures john larkin <jl@glen--canyon.com> - 2025-10-25 12:42 -0700
  Re: Operating temperatures Bill Sloman <bill.sloman@ieee.org> - 2025-10-25 04:02 +1100
  Re: Operating temperatures Chris Jones <lugnut808@spam.yahoo.com> - 2025-10-26 21:06 +1100
    Re: Operating temperatures Don Y <blockedofcourse@foo.invalid> - 2025-10-26 03:24 -0700

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