I'm off to America for a few weeks in June/July and want to pay
attention to the weather while I'm out there. We are camping, so it
makes it easy for me to leave a small weather station near the tent :-)

When I was there last, this was the kind of thing I had to look out for
for temperatures (world's tallest thermometer!):
http://www.jstottphotography.com/photo.php?s=1758

I'm not too fussed about wind or pressure (we will be gaining 10000ft of
altitude and losing it again very quickly so calibration would be nigh
on impossible), but am interested in temperature and humidity. It's not
going to rain :-)

Importantly, the device must be carryable on a plane (so no mercury
thermometers or anything like that!) and must record the minimum and
maximum temperature from when I reset it. I want to be able to find out
overnight minima of temperature.

I need to travel as light as possible, so it's got to be really small.
And waterproof too if it's going to sit outside my tent overnight.

Anyone got any suggestions?

--
Jonathan Stott
Canterbury Weather: http://www.canterburyweather.co.uk/
Reverse my e-mail address to reply by e-mail

I'd rate the Kestrel 4000 handheld AWS. I've had one for almost 2
years, it's been with me to more countries than I can remember, it's
handled Finland in December and Texas in June, and I used it to log
T/RH/PPP/ff avg/ff gust at 1 min intervals during the annular eclipse
in Madrid on 3 October last.

It's about the size and weight of a mobile phone, has all the major
elements except rainfall and wind direction (... obviously!), logs the
past 400 observations at intervals from 2 sec to 5 hr, runs for a year
off 2 AAA batteries, and is astonishingly accurate - I've left it
logging alongside my much more expensive sensors in my Stevenson Screen
for several days, and you'd be hard pushed to tell the difference. A
bit pricey (about £280 as I recall, more for the PC interface to
download the observations) but worth its weight in platinum. This is
one piece of kit I take on every business trip. (Oh, by the way, I
don't have any shares in the manufacturers ... but I wish I had!)

I bought mine from meteorologica.co.uk, but there's quite a few places
sell it and you can shop around for the best deal.

Regards -- Stephen

Stephen Burt wrote:
I'd rate the Kestrel 4000 handheld AWS.

Kestrel seem to do 4 different handheld AWSs - is the 4000 version
significantly better than the 3500?

Also, how do they cope with wildly varying altidude? I will be
travelling from Seattle to Los Angeles via the Rocky Mountains so will
be going from about 0m ASL to about 3000m ASL and back again - do you
think that it would be able to adjust for such wildly varying altitude
in such a short amount of time with regards to pressure readings?

Also, a more practical problem. If I want to leave the AWS outside near
the tent, how far away do you think it would need to be away to be far
enough away from the effects of two sleeping bodies?! Would temperature
readings be fine if the device was dangled on the tent? Also, would
there be any way to secure the device (say to a picnic table or
somesuch)? I'm wary of leaving the device outside in a public campground
for obvious reasons (although we'll be a long way from civilisation most
of the time!).

I don't want massively accurate readings, just to give me a fair
ballpark of the kind of conditions while I'm there.

--
Jonathan Stott
Canterbury Weather: http://www.canterburyweather.co.uk/
Reverse my e-mail address to reply by e-mail

I too have a Kestrel, but they are not cheap. Superbly accurate.

Jack

Kestrel seem to do 4 different handheld AWSs - is the 4000 version
significantly better than the 3500?

The 4000 logs, the lower models don't. The logging is useful for
keeping an eye on conditions when you're doing something else, like
watching an eclipse (or sleeping in a tent ... ). Price delta is about
30% - well worth it in my book.

Also, how do they cope with wildly varying altidude?

Out of interest, I have used mine a few times to log cabin pressure
during flights. The sensor and the display are very sensitive. Take it
up a tall building in a lift, the pressure begins to fall as soon as
the lift moves, and stops as the lift stops - I could not detect any
hysteresis, though there must be a second or two in there I'm sure.

Here's the first 15 min of 1 min logged data on a flight from Helsinki
to London: (it logs all elements by default, this is just the pressure
data)

4.11.2005 15:53 1014.2
4.11.2005 15:54 1009.1
4.11.2005 15:55 1001.7
4.11.2005 15:56 985.4
4.11.2005 15:57 974.4
4.11.2005 15:58 961.9
4.11.2005 15:59 946.4
4.11.2005 16:00 928.6
4.11.2005 16:01 911.0
4.11.2005 16:02 893.7
4.11.2005 16:03 879.5
4.11.2005 16:04 862.5
4.11.2005 16:05 845.2
4.11.2005 16:06 832.7
4.11.2005 16:07 822.1
4.11.2005 16:08 814.3
4.11.2005 16:09 801.4
4.11.2005 16:10 785.7
4.11.2005 16:11 777.2
4.11.2005 16:12 776.9
4.11.2005 16:13 777.0
4.11.2005 16:14 776.8
4.11.2005 16:15 777.0
4.11.2005 16:16 777.0
4.11.2005 16:17 776.7
4.11.2005 16:18 777.0

Also, a more practical problem. If I want to leave the AWS outside near
the tent, how far away do you think it would need to be away to be far
enough away from the effects of two sleeping bodies?!

Maybe it depends on what was happening in the tent ... ;-o

Would temperature
readings be fine if the device was dangled on the tent?

Apart from exposure to outgoing radiation, no reason why not

Also, would
there be any way to secure the device (say to a picnic table or
somesuch)?

there's a tripod thread (tho' that's easy to undo) and there is a wrist
strap fixing - with a bit of poking I'm sure you could wrap some thin
chain around it and padlock it. I think keeping it out of obvious view
would probably do the trick. (It comes in three colours, a drab
military-style khaki, a dark grey and a dayglo orange. I chose the
latter to make sure I didn't put it down somewhere and forget it, but
for something less conspicuous one of the others might be a wiser
choice!)

I'm wary of leaving the device outside in a public campground
for obvious reasons (although we'll be a long way from civilisation
most
of the time!).

Understood, see above. Reasonable care on security would be prudent,
but frankly most people would not know what it was ...


I don't want massively accurate readings, just to give me a fair
ballpark of the kind of conditions while I'm there.

You'll not get a better device for 5x the price or 10x the weight. You'll end up using it a lot at home too - mine is my backup pressure sensor for my AWS, for example. If you get the impression I'm a big fan, it's because I am. Frankly I bought it not expecting very much and have been truly delighted, it's a cracking little gadget!

Stephen