Another Thermometer Question

I got an el cheapo thermometer from Target that I'm planning on using during an AG batch (first one with my own equipment). I'm using it now to measure water temp for a batch of pizza dough I'm making, so I decided to check its calibration. Dunked it in an ice bath and it was a bit high, so I adjusted down to 32F. Dunked in a rolling boil, and it barely got to 202F. So, does this mean my thermometer is not reliable? Should I just scale between 32 and 202 and call it a day?
ezziey

Ice water shouldn't probably read 32, or it'd be frozen, but it should be within a few degrees if you have a lot of ice.

Water only boils at 212 at sea level. It can boil much lower the higher you go, but Raleigh isn't that elevated so honestly it should read 211-212 on the thermometer.

Usually if it's high it's high, and if you adjust it on the low end it oughta work on the high end, at least that's how it's worked for me. 10 degrees is a huge discrepancy. Might be a bad thermometer but I'm not sure.

Actually an ice water slury should and does read 32F. That is the best way to calibrate a thermometer.

I have a thermo background and know that an ice water bath should be at 32F until the ice melts or the water freezes. Boiling water _should_ be at 212F until its all boiled. Its physics. So I have a bad thermometer then? I paid like $10 for it.

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ezzieyguywuf said:

I have a thermo background and know that an ice water bath should be at 32F until the ice melts or the water freezes. Boiling water _should_ be at 212F until its all boiled. Its physics. So I have a bad thermometer then? I paid like $10 for it.

Sent from my HTC Vision using Home Brew Talk

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It's Chemistry!

Thermodynamics is a branch of physics, as far as I know. And the study of what temperature water boils/freezes at falls under thermodynamics as well...as far as I know. I know that chem and thermo overlap a little. I took a combustion class that had a lot of chem in it.

Yeah, thermodynamics overlaps into both physics and chemistry, but I believe that's technically under thermochemistry. Just splitting hairs here because I'm bored.

For the most part, we desire better accuracy at the temps we're concerned about measuring. Mash and strike temps are around 150-180F so it's better to calibrate to boiling if you don't have another reference thermo to shoot for 160F. Also, when using icewater, make sure it's a lot of ice and that you keep stirring it with the probe.

Yea, it was mostly ice and constantly stirred. I was thinking the same about maybe using the boiling reference instead of freezing, as we're more concerned with the higher-end temps. I don't think I can convince the swmbo to upgrade our thermometer currently, so I'll have to figure something out.

save yourself worry and buy this http://www.wasserstrom.com/restaurant-supplies-equipment/Product_285618

it reads as fast as the thermapen, almost as accurate (by like 0.1C) and is dead on. I have it and i calibrate with ice slurry to read 32 F then check boiling and it reads 211.5 which is exact with my altitude then back to the ice and its 32 F.

ekjohns - took your word on that - I just ordered it. Been looking for something reliable and accurate without having to shell out for the thermapen (despite hearing great things about it) - i'm on a budget!

i was in the same boat as you untill i spent a full weekend looking for thermometers and found a brewer talking about this one. It has the tappered end exactly like the thermapen which is what allows it to read so fast. The only thing to be careful with this thermometer is that you want just the tappered end in the liquid, meat, etc. If I put the thermometer further down in the liquid it will read a little off. However, i think this is cause i calibrated it with just the tip in the ice slurry. Either way play around with it a bit with ice and boiling water to get he hang of it. As far as accuarcy, speed, and ease of use NOTHING beats it

ekjohns said:

save yourself worry and buy this http://www.wasserstrom.com/restaurant-supplies-equipment/Product_285618

it reads as fast as the thermapen, almost as accurate (by like 0.1C) and is dead on. I have it and i calibrate with ice slurry to read 32 F then check boiling and it reads 211.5 which is exact with my altitude then back to the ice and its 32 F.

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question about these... if I dip it into my keggle and pull it back out how long or quickly does the temp change?

I can't be sticking my head down in there trying to read it.

-=jason=-

Yea, I think a thermometer that you could use like a stopwatch would be nice, i.e. push a button and the current reading stays.

I am on the fence $20 probe, but 10/12 shipping

-=jason=-

it changes within a sec. and it doesnt have a stop watch function so your head would have to be in there. I just use mine for mashing so the steam is like a man's version of exfoliant

See if you have a store by you they will do a free ship to store if you nice and ask them

I'm actually going to be carrying the CDN Proaccurate on my site in about a week. It is similar to the one linked but it has a hold button so you can pull it out and read it.

Bobby_M said:

I'm actually going to be carrying the CDN Proaccurate on my site in about a week. It is similar to the one linked but it has a hold button so you can pull it out and read it.

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bobby this one?

http://www.amazon.com/dp/B0021AEAB2/?tag=skimlinks_replacement-20

or the round topped one http://www.amazon.com/dp/B0021AEAG2/?tag=skimlinks_replacement-20

-=Jason=-

Flomaster said:

the round topped one http://www.amazon.com/dp/B0021AEAG2/?tag=skimlinks_replacement-20

-=Jason=-

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I have this one and it is really cool also has a peak temp button.

Shipping is:

$25.79 to Alberta, Canada for one or two
$14.50 to Montana

For any creepers wondering

gunner65 said:

I have this one and it is really cool also has a peak temp button.

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ok I'll pull the trigger on that one for $12.69 and free 2 day shipping via my Prime membership how can I pass

-=Jason=-

Yeah, that's the one I'm getting CDN-DTQ450X.

Flomaster said:

ok I'll pull the trigger on that one for $12.69 and free 2 day shipping via my Prime membership how can I pass

-=Jason=-

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It is quick reading to boot. Some of the reviews were are little bad but I took the gamble (cheap) and I really like it. I use it with my smoker too.