I have three DS18B20 sensors in my solar heating system for boiled water
since about 5 years, no other metal case than TO92.
In air it's easy. Imagine a soil after 60l/mp water and one week of rain.

On Wed, Oct 28, 2015 at 11:50 PM, Allen Mulvey <allen@amulvey.com> wrote:

> I am using some of those stainless steel types I got from
> ebay. They were originally purchased for soil temperature in
> a greenhouse but I am now using them for exterior air
> temperature. After a year in service they are doing well.
>
> Allen
>
> > -----Original Message-----
> > From: piclist-bounces@mit.edu [mailto:piclist-
> > bounces@mit.edu] On Behalf Of James Holland
> > Sent: Wednesday, October 28, 2015 12:14 PM
> > To: piclist@mit.edu
> > Subject: RE: [EE] Soil temperature sensing methods,
> > thermodynamics
> >
> > > From: James Cameron <quozl@laptop.org>
> > > Subject: [
> > > To: piclist@mit.edu
> > > Message-ID: <20151028021328.GB2367@us.netrek.org>
> > > Content-Type: text/plain; charset=3Diso-8859-1
> > >
> > > I'm curious as to the thermal resource beneath me.
> > >
> > > I've dug a 500mm deep hole and inserted a tube, 1m long
> > 33mm diameter
> > > 2.16mm wall thickness, with caps at both ends.  The tube
> is
> > straight
> > > plastic pressure piping for water reticulation.  I've
> set it
> > vertical
> > > using a spirit level before backfilling the hole.
> > >
> > > I'm planning a 600mm long tube over the exposed half for
> > blocking
> > > sunlight, with air vents.
> > >
> > > How to restrict the thermally induced air flow within
> the
> > tube?
> > >
> > > Is there any value in sensors at different heights?
> > >
> > > I'm most familiar with DS1820 series sensors.  Are there
> any
> > sensors
> > > more suited to this application?
> > >
> > > p.s. ground here has not frozen in living memory, winter
> > frosts only
> > > affect grassed areas, and only for a few hours.  Surface
> can
> > be 65?C
> > > to 75?C on a calm day in summer.
> > >
> > > --
> > > James Cameron
> > > http://quozl.linux.org.au/
> >
> > You can get the 18B20 sensor potted in a stainless steel
> > housing, maybe you could just bury one or two of those in
> the
> > ground. There are plenty of vendors, I just picked this
> one at
> > random as an example:
> > http://www.ebay.co.uk/itm/2x-DS18B20-1M-Waterproof-
> > Sensor-Digital-thermometer-Thermal-Probe-Arduino-
> > UK/331626763281?_trksid=3Dp2141725.c100338.m3726&_trkpar
> > ms=3Daid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%
> > 3D20150313114020%26meid%3Deccc7aeef0274a3e9e751d44
> > c7ae2bd9%26pid%3D100338%26rk%3D6%26rkt%3D9%26sd%3
> > D190784248550
> > James
> >
> > --
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> > archive
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