Oct 29, 2013 at 9:34 pm #1309272
Maia JordanBPL Member
@maiaLocale: Rocky Mountains
Companion forum thread to:Oct 29, 2013 at 10:04 pm #2039292
Jerry AdamsBPL Member
@retiredjerryLocale: Oregon and Washington
Good article Rex.
I have one of those thermometers/compass on the outside of my pack also. Cheap, light. I measure the temperature of ice water bath and write down the freezing temperature on it's side to calibrate because they're not real accurate.
I have an ADC Wind that also measures wind speed, except I ran over it with my car so the wind speed doesn't work anymore. I like that it also has date, day of week,…
The only problem with ADC wind, is the sensor is buried in it somewhere so it takes a long time for the temperature to stabilize.
I bought some cheap unnamed temperature/wind speed meter from amazon.com. It's temperature sensor is visible inside a hole so it's protected, but stabilizes pretty quick.
I stole my wife's kitchen thermometer (don't tell her). Similar to yours. Quick to achieve temperature. You can put it in water. It's off by 1 degree F so I just wrote the freezing temp (31 F) on the outside.Oct 30, 2013 at 5:31 am #2039339
Ken T.BPL Member
Here is one that is accurate and stores information. Data loggers for the food industry. Pocket sized. Those mercury/alcohol ones some times don't go low enough. A bunch of the electronic ones seems to stop at -18 FOct 30, 2013 at 6:47 am #2039356
I question laying the thermometer on the ground could that not effect the reading if the ground temp is different from the air tempOct 30, 2013 at 7:17 am #2039367
"This year I started carrying an Acurite Digital Window Thermometer which is 34 grams without the suction cup. This battery-powered thermometer records the minimum and maximum temperature, resetting every 24 hours after powering on. At camp, I set the thermometer on the ground just outside the tent. In the morning, I note the overnight low temperature on my voice recorder. The maximum temperature is almost useless for backpacking. One day the thermometer recorded a high temperature of 94 F (34 C) inside my white cuben fiber backpack, when a nearby weather station recorded a high temperature of 64 F (18 C)."
I like the advertised features of this thermometer but why do you still carry it if it is off by 30* for daytime highs?Oct 30, 2013 at 9:18 am #2039415
David GardnerBPL Member
@gearmakerLocale: Northern California
I carry an old REI zipper thermometer (no compass), which I use to measure water and air temperature so I can estimate the right amount of alcohol for boiling water.Oct 30, 2013 at 9:37 am #2039427
I have the Acurite and like it; someone else on the forum suggeted removing the clear plastic case and placing the thermometer unit in a small plastic bag. I think that would drop the weight considerably. I've found it to be pretty accurate.Oct 30, 2013 at 9:41 am #2039429
John S.BPL Member
Most of those carrying therms only want to record the overnight lows.Oct 30, 2013 at 10:03 am #2039436
Michael RayBPL Member
> I like the advertised features of this thermometer but why do you still carry it if it is off by 30* for daytime highs?
The temp inside his pack was artificially inflated because of sunlight even though the pack is white.
I use the Coghlan's Digital Dangler. It's known for being about 3* off so I just adjust accordingly. I try keeping it in the mesh pocket away from the sun and seemed to do OK. Sometimes my water bottle would throw it off.
I'd agree that laying it on the ground would skew the results.
I also learned it's much hotter in the car itself than the trunk! Now any electronics we're not taking get stowed there instead of the glovebox.Oct 30, 2013 at 10:14 am #2039439
Michael GonzalesBPL Member
Good to see that I am not the only one who packs a thermometer. I have a trip diary in which I record all my backpacking trips. A key piece of data I record is the temperature. I utilize this data to evaluated my gear and fine tune my gear based on the predicted temperature on my excursions. The Accu-rite thermometer that I use has a long battery life and the min/max temperature feature has been very useful. I removed the suction cup and store the battery in a separate clear round case when not in use. In my value system the benefits I get from my Accu-rite outweighs the nominal weight penalty.Oct 30, 2013 at 10:46 am #2039455
Alex HBPL Member
@abhittLocale: southern appalachians or desert SW
I have also carried one for decades and it has helped in fine tuning the system especially as I am almost always out in the shoulder and winter seasons. If I just did summer trips I probably would not bring one.
Official temperature records are taken at 5 feet above ground in a ventilated box out in an open area with the thermometer in the shade of the box. I do check the highs several times each day just to see but make sure the thermometer is in a shady place above ground. I too have had wild readings when hung on the side of the pack, even in a mesh pocket.
At night I usually hang it suspended from one of my poles to get a bit more accurate reading as it relates to temperatures recorded at nearby stations rather than just laying it on the ground. Of course we are laying on the ground so who is to say what is more relevant?Oct 30, 2013 at 10:49 am #2039458
I'm interested in one for the same reasons Michael mentioned; it's nice to be able to know the limits of your gear.
I follow Shug's videos on YouTube. From what I can tell, he uses a dual sensor thermometer which will read the highs/lows from under his tarp and outside of his shelter.
One feature of the Garmin Fenix that really appeals to me is the temperature sensor but I'm concerned about the battery's life span and cost to replace when it no longer holds a charge. I'll check out the accurite in the meantime.Oct 30, 2013 at 10:49 am #2039459
@fluffinreach-comLocale: no. california
nice write up .
in my walks i have found that there can be as much as a 6° night time differential inside to outside even with a mostly netting inner tent. and that my feet go numb at 56° temp inside the boots.
having a thermometer with an additional remote sensor makes finding our such valuable trivia more fun !
v.Oct 30, 2013 at 11:00 am #2039467
Thanks for the article Rex. Voice recorders, now thermometers. . . I feel like I should out-geek you with an article on the best backpacking slide rules.
>"I felt colder on some nights that were several degrees F warmer than others, according to the max-min thermometer. I think the difference was a slight breeze, despite using the same sleep system."
I notice I feel a lot colder despite the same dry-bulb temperature when in a creek drainage. Cold air can be falling downslope, generating a breeze near a moderately-sloped stream.
The other big variable I find is cloud cover versus clear skies. That makes a 5F, even 8F difference for the same air temperature. We are close to equilibrium with clouds – we radiant away infrared heat, the ground, trees, and clouds radiant infrared heat back at us. But on cloudless night, grass, trees, tents, and people are radiating infrared heat away into space while getting almost nothing back. (Overly technical point: while deep space is 3.2K (-453F), and clear air is mostly transparent to IR, the water vapor in the atmosphere does radiant a little. I've measured sky temps by IR of 30F on a 70F clear day and -45F on a cool, 30F winter day.)
>"I question laying the thermometer on the ground could that not effect the reading if the ground temp is different from the air temp"
You can tweak what you are measuring by how you place the thermometer. If you wanted a good air temperature, I'd place the thermometer in a tree, a few feet off the ground. That avoid the radiant losses discussed above. If you want to include those radiant losses on a clear night (so the thermometer reports what your tent or bivy is experiencing), then place it in the open. Rarely would the thermometer be in good thermal contact with the ground, so the big factors are if it is in the wind it will record close to air temperature. If it sees open, clear skies, it will record low due to those radiant losses. Putting under a tree or "shading it" from the clear sky with a branch, stone, or pot lid would get it back to recording close to air temperature.
Bringing two thermometers (or playing at home as I do) and placing one on top of your car while another is under your car, for instance, and you'll see the magnitude of the radiant heat loss on different nights. Windy and cloudy – little effect. Still air and clear skies – huge difference.Oct 30, 2013 at 11:23 am #2039477
Multiple use, right?
I have a small digital alarm clock, and I use it because it is much louder than a wristwatch alarm. I hang it on the front pole of my tarp shelter where it is about two feet off the ground, but it is subject to most of the weather blowing by. The second feature on it is a digital thermometer. So, when I wake up from cold in the middle of the night, I only have to raise up on one elbow to see the temperature.
Being a proper geek, I keep it on the Celsius scale so that I can compare notes with David.
–B.G.–Oct 30, 2013 at 11:26 am #2039480
John KlinepeterBPL Member
@johnzotkLocale: Northern Rockies, USA
For several years I also used a Digital Dangler. It performed well but eventually some of the LCD segments became "wonky" so I retired it. For the last few years I have used a control3.com/4145 two channel min/max thermometer which weighs 1.2 oz. with the battery.
The two channels allow one to measure in-tent and outside temps simultaneously. I have seen some very interesting outside minimum temps and don't know how to interpret them. As a consequence I trust the in-tent readings more than the exterior readings. Exposure to the naked sky on clear nights would seem to be the culprit. The readings have been taken on the ground or with the sensors perched a couple inches off the ground in tufts of grass using floorless shelters. I don't worry much about air vs. ground temp differences after reading one of R. Nisley's graph presentations several years ago that showed little difference between the two at least down to several degrees C below freezing (see http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=20434).
Edit: to add link to two channel thermometer here http://www.control3.com/4144p.htm
Note that the device is available in degree F and degree C configurations as separate model numbers.Oct 30, 2013 at 11:36 am #2039486
Stephen MBPL Member
@stephen-mLocale: Way up North
My weapon of choice is a Kestrel 2500 Weather station, I like that the wet bulb thermometer gets a pop reading stright away, the coldest it has seen it -13F, I use the aenometer and altimeter on it a lot.Oct 30, 2013 at 12:11 pm #2039500
>"Multiple use, right?"
I'm thinking a digital watch, with thermometer (which might record high/low, and/or graph the data) could be converted to a zipper pull, thereby saving the weight of the strap and eliminating the falsely high readings from being on your wrist.
-watch (and therefore a compass if the sun is up)
-alarm (beat the sun to the snow field, make your return flight)
-hygrometer (a few have that)
-altimeter/barometer (rarer and more expensive) but really handy for route finding and weather prediction.
I haven't done an extensive survey, but when I think "thermo-alti-barometer watch", I imagine a big, honking men's watch. I've always preferred a women's sport watch because they do all the same (basic) things at 1/2 or 1/3 the weight and fit my dainty wrist just fine.
I did just now find a ladies watch with thermometer: -10 to 60 C (14 to 140 F), 100M Water Resistant, Digital Compass, Displays sunrise time and sunset time, LED Backlight, analog (nice for use as a compass) and digital (nice for timing or alarms), $79. http://www.ebay.com/itm/CASIO-Digital-Ladies-SGW500-1B-Compass-Twin-Sensor-Sport-Ana-Dig-Watch-/200979152003?pt=Wristwatches&hash=item2ecb4a7c83
Here's one already on a clip: $41, digital UV detector, a digital tide function and a digital thermometer sensor. Electro Luminescence. http://www.amazon.com/Tide-Sensor-Clip-Orange-Detail/dp/B001CGSIBO/ref=pd_sbs_watch_1Oct 30, 2013 at 12:18 pm #2039502
"Thermometer watch as a zipper pull"
I can't use a thermometer on the zipper pull, because that is where the slide rule hangs.
–B.G.–Oct 30, 2013 at 12:26 pm #2039505
So use the slide rule as a tie bar or hair clip and free up the zipper for the thermo/watch.Oct 30, 2013 at 1:13 pm #2039518
"tie bar or hair clip"
Surely you jest. I can't imagine a backpacker wearing a necktie. A hair clip requires that we have head hair.
When you take your trail slide rule, do you take a spare cursor along?
I found that it was lighter to take a bunch of printed log tables on the back of my topo maps.
–B.G.–Oct 30, 2013 at 1:28 pm #2039523
Stephen OwensBPL Member
@walknhighLocale: White Mtns, AZ
I carry a fishing thermometer (glass tube w/aluminmum class) works just as well in water or air. Other than fishing, I use it to calibrate my preciption of temperature.
From anatomy class I learned the body does not measure an actual temperature, it preceives temperature by determining whether it is loosing or gaining heat to an object or the environment. This is why you feel chilled when you have a fever, because heat is radiating from your body, you preceive it as a chill. Or why water and a piece of wood at the same temperature feel different, water conducts heat better than wood. Now that is geeky.Oct 30, 2013 at 1:43 pm #2039529
Jean SwannBPL Member
@angelfireLocale: Middle Georgia
I use the Acurite Digital Window Thermometer, without the suction cup. True, it is a bit heavy at 1.2 ounces, but its usefulness exceeds its weight penalty in my opinion. I usually have a tiny digital camera with me, so each morning I shoot a photo of the campsite (which helps me keep the details of my trip straight) and a photo of the thermometer, showing the previous night's low temp.
Sometimes the weather is not conducive to reading the thermometer first thing in the morning!Oct 30, 2013 at 1:48 pm #2039531
John S.BPL Member
The body does measure the temperature of blood in several areas including the brain. The hypothalamus is your thermostat.Oct 30, 2013 at 3:08 pm #2039558
@rcaffinLocale: Wollemi & Kosciusko NPs, Europe
> I feel like I should out-geek you with an article on the best backpacking slide rules.
I have a very nice 6" Fuji slide rule. Full function, 22 g. Does it count?
Only one cursor though.
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