Group buy of stick on tape thermometers?

[Ryan “Rudy” Oury]

i just posted for this GearSwap also. I’m gauging interest in a small group buy of stick on tape thermometers. They’re ~$2 each but w/ a min order of 20.

they read from 75-212F and the intention would be to put them on the lid of your cook pot to monitor water temp. Call me crazy, I just like knowing what temp my water is at :)

we can discuss the merit of this idea here, BUT for my sanity, if you’re interested in participating in the group buy, please post that in the GearSwap thread, not here.

http://www.telatemp.com/p/492/

[Jack]

Do you think the adhesive would hold up to the heat?

[Ryan “Rudy” Oury]

Im sure the adhesive will be able to do at least 212 since that’s how high it will read. I’d expect the manufacturer designed the glue to handle a bit more, like 240-250F, to make sure it didn’t come off easily.

i plan on putting mine on the lids of my pots (rather than the side of the pot) since I bet the heat coming up the side of the pot would probably be too much for it. We’ll see though.

[Ben H.]

The problem with putting the thermometer on the lid, is it won’t be a good indication of water temperature.  The thermometer will be stuck to and grounded to the aluminum lid.  It may see hot steam on one side but the reading will not indicate that temperature.  It will indicate the lid temperature which I can touch with my fingers for an awful long time on a pot of boiling water.

[Ryan “Rudy” Oury]

Certainly it’s not going to be a 100% accurate measurement… the only way to do that is to sticking something in the water. but it’s the only viable place this sort of device can go. The sides of the pot have a whole slew of issues as well (false heat reading  of stove “exhaust” gases, can’t see it if fully inserted in a cone or tall windscreen, exhaust gases may be too hot for adhesive).

hit we’ll see. This may be a big waste of time but ant least it won’t cost anyone more than a couple bucks.

[DAN-Y/FANCEE FEEST]

Exhaust gases from a stove go up the side of the pot and then curl over the top onto the lid. ;-)

[DAN-Y/FANCEE FEEST]

So, the stick on will give false readings.

[DAN-Y/FANCEE FEEST]

Looking for some feedback on how well these stick-ons are doing. Curious minds want to know :-)

[Ryan “Rudy” Oury]

Sorry for the radio silence the last couple days. And sorry for what’s going to be a long post. Basically, I placed a small order and was waiting for them to arrive in order to do a little testing. I wanted to see whether the nay-sayers who doubted that this would work, were right. Finally got them today and just ran about 10 tests. The results are… mixed.

First and most importantly is weight… even taped to a strip of aluminum from a can, my scale doesn’t even register a single gram. So these do qualify as super mega ultra light :)

But biggest issue is that the ones I ordered are not reading as I expected them to. The website seemed to indicate there would be color variations to indicate temps and it there would be at most 3 of the temp bands “lit up” at any time. As it turns out, ALL bands warmer than the current temp are just green, and they turn black when the temp is ~5F warmer than that band. No discernible color variations other than black and green (even to my artsy wife who sees color subtleties far better than me). So when they’re sitting on my counter at 70F, ALL bands are green. As it warms you basically read the lowest green band. That sounds fine (or at least good enough), BUT the bands are very hard to see w/o a light shining directly on them. Second “product” issue is that I didn’t notice that the graduations of temp go by 10F from 100-180 (large, but acceptable), but then jump to 20F for the last two (unacceptable). So once the 180 goes dark (at ~185F), you have little indication of temp change to boiling. I live at 7500′ so boiling is generally ~198-200F, thus the thermometer does nothing for me in the final stages.

As for actual function, given the noted product limitations… I think measuring water temp via the lid actually worked decently well. I tested water temp, “air temp” (in the pot, below lid) and then had a strip taped to the lid, tracking all 3 simultaneously. The strip tracked the air temp in the pot very closely. So the concerns that the lid wouldn’t heat up enough, or the exhaust gases would curl over the top heating too much, turned out to be invalid. Of course, the air temp in the pot does lead the water temp (by 15-25F at points), but it starts to even out over ~175-180. And if you did a couple tests to see how the strip tracks w/ your pot/lid combo, knowing that when its reading 170, the water temp is ~150, it could be helpful.

I tried a couple other methods too. As noted above, I taped a temp strip to a strip of aluminum from a pop can and just set the strip IN the water (slid between the lid and pot). As expected, this tracked the water temp very well, and it didn’t seem like the glue loosened. The problem w/ this method is that you either have to remove the lid to read the temp (losing efficiency and I REALLY wanted to read by just looking at the pot) or you have to pull the strip out of the water/pot. This might not seem like a problem BUT it turns out these strips react VERY quickly and a strip of aluminum can doesn’t retain heat very long. Basically the strip cooled within ~1 sec, faster than you could get a reading.

One interesting thing to note on another method is results for placing the strip on the side of the pot. It was definitely a failure. The heat from the stove exhaust had the strip reading over 150F before my water had warmed 10-degrees. And many of us have windscreens that cover the sides anyway so the strip can’t be read there.

So the long and short of it is that I think measuring temp on the lid IS a viable temperature measurement method (though certainly not perfectly accurate), BUT I ordered the wrong product. Looking back at the first one I’d found (from http://www.telatemp.com), it looks like that would be a better version (consistent temp graduations and clearer temp indication). The larger size isn’t an issue as these weigh virtually nothing and are cut-able.

But while the initial “interest” total was pushing 80 strips (so telatemp’s 20 strip minimum order isn’t an issue), I’ve laid out almost $40 at this point experimenting (shipping was $20!) and am not too interesting in placing another order (which will be $50-60 minimum) w/ the uncertainty of how the other strips will work.

If anyone wants to buy these strips off me (I have 8 unused left), and/or people are still interested in the OTHER strips, I’d be willing to facilitate the order still. But if I had to do another order to test the second strips, I’d have to resell them w/ an “upcharge” to recoup some of my costs at this point.

[Ryan “Rudy” Oury]

And sorry for what may sound like an odd post… I had gone to the post thru “My Profile” and thought this was a reply in the GearSwap thread, no the MYOG thread. All facts apply, but the notes at the end about ordering, etc are geared toward that audience.

[David Thomas]

It seems to me that you’ve developed a good way to be more fuel efficient.  It’s so easy let a pot get too hot or even boil over because (1) every removal of the lid loses heat, (2) it’s tedious to lift the lid and look every 20 seconds, (3) it’s hard to tell by looking how hot the water is, and (4) therefore hard to estimate how long to wait for the next check.

Stuck to the lid, I’d expect a pretty consistent relationship to the water temperature in the pot.  And that you would quickly learn that “130F” was a good temperature for making hot chocolate while “170F” was better for rehydrating FD food.

[Author]

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