Useful small, cheap, digital thermometer

matthew

matthew

Well-known member
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My bikes don't have an onboard thermometer and I like knowing what the outside temperature is when I'm out riding.

I've purchased a few of these and they work well.

$2 with free shipping


http://www.ebay.com/itm/Digital-LCD...t=LH_DefaultDomain_0&var=&hash=item4d20384de5

5jy5n5.jpg


I leave it inside the clear map pocket of my tank bag and I let the temperature probe hang a few cm outside the pocket. I suppose it could be ghetto hard mounted using double sided tape or some Velcro as well
 
Make sure it doesn't have any moving air over the probe while riding or it will register windchill (or register a lower temperature than it is).
 
Nice - I got one that is also voltmeter (few more dollars) - I fed the temp probe into the nose of the bike, so it sits just to the side of the inlet grille, under the headlight. Same bike, you can try it...
I first had it secured near the handlebars, but it was giving me too high of a reading, as engine heat was going into this area.. much more accurate in the nose cone :) It stays there, I had it ghetto mounted to my GPS, and it is hard wired anyways...

I love having this on my bike, such a simple thing to make me happy.
 
Gosh...I wonder what would happen if you got rain/humidity on the probe then and then say....had wind-flow evaporate the rain faster than it would in stiller air. What does Wikipedia say about that?

Weather station thermometers are usually in housings protected from the elements. Rain makes the readings unreliable, wind plus rain will do a bit more.
 
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jc100 said:
Gosh...I wonder what would happen if you got rain/humidity on the probe then and then say....had wind-flow evaporate the rain faster than it would in stiller air. What does Wikipedia say about that?

Weather station thermometers are usually in housings protected from the elements. Rain makes the readings unreliable, wind plus rain will do a bit more.
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Thermometers are not affected by moisture or humidity in the air. We feel wind chill because we lose heat due to the evaporation of moisture on our skin. Thermometers don't generate their own heat, therefore they don't experience the same cooling effect that we do.

If you compare a thermometer exposed to ambient air to a thermometer sealed inside a box, you'll notice that the sealed thermometer will lag behind the ambient thermometer because it takes longer to change the temperature of the trapped air. That would be the only reason for "unreliable" temperature results. If you allow the sealed thermometer enough time to "heat-soak" (approx. 1 hour), then you'll see that both thermometers would read the same value (assuming that the ambient temperature has not changed).
 
I bought a bunch of those exact thermometers. They all seem off to me because they read differently than my thermostat in my apartment but maybe the thermostat is off. From comparing by "feel" (I know, terrible to go by), the thermostat seems to match the thermostats I've used in hotels but maybe not. I set 3 of them up in the same place once and they all read the same (still different from the thermostat) so at least they're consistent.

I put one in my fridge door, one in the freezer, one in the top of the fridge, and one in the bottom of the fridge. My fridge is a POS so I wanted to make sure I didn't have any hot spots where food could go bad. Then the one on top of my thermostat.

I really should just borrow a calibrated thermometer from work that we use for testing the weather systems we install that are used by environment Canada. That would definitely tell me which is accurate, heh.
 
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Thermometers are not affected by moisture or humidity in the air. We feel wind chill because we lose heat due to the evaporation of moisture on our skin. Thermometers don't generate their own heat, therefore they don't experience the same cooling effect that we do.
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You are incorrect, moisture on a thermometer evaporating will certainly cool the thermometer so yes it will react.
Once the thermometer is dry tho it will read correctly.

If it's raining and you are moving it will read cooler, it generally will not react to humidity in the air.
Something like fog would be interesting to experiment.
 
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So anyway, if anyone wants to know what the temperature is while they're out riding, purchase a few of those thermometers. For $2 and free shipping, you can do a lot worse with your money
 
MacDoc said:
These are passive - no battery? I do miss having a thermometer
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They have batteries.

Pic from the auction:
121217_re_ther_03.jpg


From the description:
Power by: 2 x LR44 button batteries.*
 
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I just bought 10 LR44's from Amazon.ca for 4.40 all in (shipped from hong kong). If you bought LR44's in canada, they would cost many times what you paid for the thermometer. 50 was even cheaper (per battery), but who needs 50 batteries?
 
Dollarama sells them. I think it was $2 for 5.
 
matthew said:
incorrect.

http://en.wikipedia.org/wiki/Wind_chill


Wind-chill or windchill, (popularly wind chill factor) is the perceived decrease in air temperature felt by the body on exposed skin due to the flow of air.
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To be more specific, its when a moist body loses water due to evaporation. This is the chilling effect.


Btw, is that thermometer waterproof?
 
Great with a probe too, so doubles as an emergency roadside rectal thermometer.
 
IMO road temperature is more important than air temperature. Black ice potential if the road is at freezing temps.
 
nobbie48 said:
IMO road temperature is more important than air temperature. Black ice potential if the road is at freezing temps.
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That may be the case but good luck finding a device to put on your vehicle to measure road surface temp...
 
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