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