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Thermometer Recommendations


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I have a two-part question for seasoned chandlers (no newbies, please!)

In another thread, catlover asked me a good, simple question of interest to all candle makers that I did not qualified to answer:

Have you found any particular type (of thermometer) to be more reliable?
Since I'm not a prolific chandler, I hope that others who have been making lots of candles for many years will share their experiences on this subject.

I have been using el cheapo thermometers from the kitchen departments of WallyWorld, the grocery store, etc. - two are digital, several are the coil "dial" type and one mercury candy thermometer (at least 30 years old!). Obviously, their accuracy is hit & miss, so I see a potentially good reason to get off my wallet and buy some higher quality thermometers IF paying more nets a more accurate, long-lived instrument.

The way I tested mine was to stick them in water brought to a rolling boil, which, at sea level, should read 212°F. I found that no two of them read the same, none read 212°F and that there was a 12° difference among them! :shocked2:

So, my questions are:

What type/brand of thermometer have y'all found to be more accurate over a long period of time?

In your opinion, does spending more really offer greater accuracy and longevity or should one stick with many el cheapos that one tests regularly and discards when they begin lying?

TIA :)

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I'm still pretty much a newbie, but the thermometer issue is one that I tackled pretty early on.

Bought a Yaley thermometer at Michael's Art store. Mercury, clipped into the double boiler pour pot.

I think it was accurate in the area it was located in on the side of the pour pot. It broke easily one day when I just set it down. I bought another mercury thermometer from another company. Same story.

Then I looked into digitals. They were $109 at the candle supply websites.

Bought one on E-Bay from China for $14.95. Took three weeks to arrive on the slow boat.

I haven't looked back since. This thing at the pull of a trigger (and sweaping around) reads real time anywhere in the pot. Yeah, its different at different locations. If I am concerned about the clear liquid where the IR beam hits, I just place a stir stick in the wax, let it heat up, and shoot the wax itself with the stir stick below it. Readings are consistent with surface temperatures.

I tried it in many other locations, the walls, the office, the parking lot on a hot day, the AC ducts. Its great.

No cleaning up later from the wax on the glass, no breakage.

My monitor is 90 degrees. The pool in a container candle about 169 and the flame seems to read around 337, but that's hard to shoot.

Release the trigger and the last temp holds on display until it auto shuts off. Can save a few numbers. Backlight for night time. C or F.

Pretty basic and pretty inexpensive. It is an "Infrared DT-380" with range from -50C to 380C.

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I respect that you specifically asked for input from candle veterans, and I admit that I am not that. But I'm gonna puff myself up with my mechanical engineering background and my experience with instruments and measurements, calibration, and accuracy. So there! :P

Anyway, I highly recommend an item like this: CND Probe Thermometer With Timer/Clock

31s6NP2-ScL._SL500_AA300_.jpg

My first one lasted 10 years in the kitchen and I think the thermocouple probe finally fizzled out. I bought five more on eBay for about $16 each so I'll have backups. I have each one labeled and I've set one as my primary, and have marked the others with their temperature offsets from the primary.

What I like about these is you can set a high temperature alarm, and a low temperature alarm. So if the wax gets too hot, the alarm goes off, and it will also go off when it reaches my ideal pouring temperature. I LOVE THAT!!!

I've bought and tested other probes, but these are my favorites by far.

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I respect that you specifically asked for input from candle veterans, and I admit that I am not that. But I'm gonna puff myself up with my mechanical engineering background and my experience with instruments and measurements, calibration, and accuracy. So there! :P

Anyway, I highly recommend an item like this: CND Probe Thermometer With Timer/Clock

31s6NP2-ScL._SL500_AA300_.jpg

My first one lasted 10 years in the kitchen and I think the thermocouple probe finally fizzled out. I bought five more on eBay for about $16 each so I'll have backups. I have each one labeled and I've set one as my primary, and have marked the others with their temperature offsets from the primary.

What I like about these is you can set a high temperature alarm, and a low temperature alarm. So if the wax gets too hot, the alarm goes off, and it will also go off when it reaches my ideal pouring temperature. I LOVE THAT!!!

I've bought and tested other probes, but these are my favorites by far.

Sounds really nice, might have to get one. Love the alarm part of it...

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I respect that you specifically asked for input from candle veterans, and I admit that I am not that. But I'm gonna puff myself up with my mechanical engineering background and my experience with instruments and measurements, calibration, and accuracy. So there! :P

Anyway, I highly recommend an item like this: CND Probe Thermometer With Timer/Clock

31s6NP2-ScL._SL500_AA300_.jpg

What I like about these is you can set a high temperature alarm, and a low temperature alarm. So if the wax gets too hot, the alarm goes off, and it will also go off when it reaches my ideal pouring temperature. I LOVE THAT!!!

I use this same one. Got if from a pampered chef party. Love the alarm. I set it at 185* even tho, I heat my wax a little higher. But if I get side-tracked, then this is a reminder!!

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I guess it is good to point out that the lasers measure surface temperature (wherever the dot lands) and the mercury ones or the digitals with a probe can measure below the surface. Since I don't mix a lot of wax at a time the surface temp seems to be ok. I suppose if I had a deep pot I might be interested in temperatures below the surface. Then again, a few good stirrings can help minimize that concern.

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... IF paying more nets a more accurate, long-lived instrument.

The way I tested mine was to stick them in water brought to a rolling boil, which, at sea level, should read 212°F. I found that no two of them read the same, none read 212°F and that there was a 12° difference among them! :shocked2:

In your opinion, does spending more really offer greater accuracy and longevity or should one stick with many el cheapos that one tests regularly and discards when they begin lying?

TIA :)

Been making paraffin candles for 15 years, soy about 6 and well into 3 for palm. I use el cheapos - the $6 dial type that I can clip on the side of a presto or pour pot. I pour paraffin and palm hot. When pouring soy I go more by the consistency ~ and pour at the "just-getting-cloudy" stage. Actually, come to think of it, I only use it to make sure the wax isn't overheated and as an indicator of when to add my FO.

I've found that pinpoint accuracy is not a necessity. And please let me make an observation about calibrating the thermometers. Barometric pressure plays a big roll ... and I can't see checking the weather channel every time I pour. Here's a link ... and, Stella, may have been the reason none of yours registered 212F that day or even that hour!

http://www.thermoworks.com/software/bpcalc.html

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I respect that you specifically asked for input from candle veterans, and I admit that I am not that. But I'm gonna puff myself up with my mechanical engineering background and my experience with instruments and measurements, calibration, and accuracy. So there! :P

Anyway, I highly recommend an item like this: CND Probe Thermometer With Timer/Clock

31s6NP2-ScL._SL500_AA300_.jpg

My first one lasted 10 years in the kitchen and I think the thermocouple probe finally fizzled out. I bought five more on eBay for about $16 each so I'll have backups. I have each one labeled and I've set one as my primary, and have marked the others with their temperature offsets from the primary.

What I like about these is you can set a high temperature alarm, and a low temperature alarm. So if the wax gets too hot, the alarm goes off, and it will also go off when it reaches my ideal pouring temperature. I LOVE THAT!!!

I've bought and tested other probes, but these are my favorites by far.

Let's see if Stella taught me how to do this right:laugh2::laugh2:

Jonsie you are a hit more power to ya girl.:yay:

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Let's see if Stella taught me how to do this right:laugh2::laugh2:

Jonsie you are a hit more power to ya girl.:yay:

You are such a dear! Thank you so much!

But again, with complete respect to Stella and the veterans here who've fought many candle battles so I wouldn't have to... I'm realizing consistent candles can be achieved without fancy thermometers.

However, I think an item like this has saved me time because of the alarms on it, and time for me is money.

I also prefer digital simply because that is my nature. I'm a neurotic digit head, and I want to KNOW the temp, and be able to read it easily.

So please know I don't mean to presume that I know more about chandling, because I sure as hell don't. But this little gadget has been a great source of peace of mind for me when everything else is so variable.

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Yeah, good point about boiling temp and calibrating.

Not just sea level, but standard pressure of 29.92 inches of mercury. As pressure goes up, so does the boiling temp of water. As pressure goes down, so does the boiling point of water.

Increase in altitude results in decrease in pressure and temperature. Without getting all einsteiny about dry and wet adiabatic lapse rates or atmospheric layers, or pressure areas (pilots know this stuff), let me suggest that our modern vacuum mercury or digital candles are not effected by these things.

However, if you want to check your thermometer for accuracy by boiling water, then you do need to make all of these changes.

Barometer readings of 29.92 (one standard atmosphere) inches will be reported for all altitudes below 18,000 feet.

That doesn't mean in Albuquerque NM that at 5,000 feet when the report is 29.92 that you really have sea level pressure. It means you have the standard lapse rate (dry usually) for what the normal pressure would be at 5,000 feet if it was a standard day.

This is what got the McDonald's manager in trouble with Stella Liebeck. At 5000 feet with standard pressure, boiling is probably closer to 205, not 212. With a low pressure area, it could dip below 199 degrees. So the actual measured temperature and calculated temperature of her hot coffee was way more than any of us could possibly endure.

So if you want to calibrate your thermometer, you need to make some calculations that go beyond altitude and pressure. You need to know the hygrometer readings and what the dry/wet lapse rates are for your exact location... and some more. These are all things that relate to air density and density altitude.

Best way to calibrate your thermometer is to send it to a lab for certification. It might not cost you more than a few bucks. Technicians do it all the time. I can get a multimeter or an altimeter or a barometer or a hygrometer or a torque wrench calibrated pretty inexpensively.

I have no doubt whatsoever that thermometers can read 12 degrees apart or more. Where the printed lines on the card are located in relation to the mercury tube can vary radically. The digitals seems to be less variable, but there is really no way you can calibrate any of these at home.

If you try and it looks close, go for it!

(Helicopter pilots really do pay attention in class from time to time.)

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Originally Posted by Judy, USMC

let me make an observation about calibrating the thermometers. Barometric pressure plays a big roll ... and I can't see checking the weather channel every time I pour. Here's a link ... and, Stella, may have been the reason none of yours registered 212F that day or even that hour!

http://www.thermoworks.com/software/bpcalc.html

I mentioned "at sea level" because I knew someone would point out that water doesn't boil at the same temperature at higher altitudes... :)

That thermoworks site is nuthin' but cool!! I knew that altitude made a difference because I compulsively read the high altitude instructions on cake mix boxes, but I had no idea that barometric pressure made such a big diff! So lemme see here... I gotta try this... :tongue2:

According to WAFB (a semi-local news station), the average barometric pressure here ranges from 29.85 mb - 30.20 mb. The FEMA Flood maps say I live at a lofty 13 feet above sea level. So, according to thermoworks, this means my water boils, on average, from 211.88° - 212.45°. Since I can't see worth a crap anyway, and would never notice the .45° more or .12° less on the dial, that's close enough to 212° for my amateur scientific purposes. ;)

Interestingly, the barometric pressure value reported by our local weathercasters has already been adjusted to sea level, according to the information on this webpage I found...:read:

http://www.usatoday.com/weather/resources/askjack/wfaqpres.htm

Q: When the barometric pressure is given for Denver, is that the actual pressure or is it corrected to sea level by some formula?

A: The pressure reported for Denver, or any official observation station for that matter, is not the actual pressure on the surface, but rather is the pressure corrected to sea level.

:confused: Hmmm... I wonder if thermoworks took that into consideration when it requested the local barometric pressure & altitude... and why would all this matter anyway?

Q: How does air pressure affect the temperature at which water boils?

A: Water boils at lower temperatures at lower air pressures. This is why water boils at lower temperatures at high elevations, such as in the mountains, where the air pressure is lower... At higher elevations, the atmospheric pressure is less than at lower elevations. This means that the saturation vapor pressure needed to allow bubbles to escape into the air is less, which means that the temperature water must be heated to in order to bring it to a boil is also less... Cooking things in boiling water at higher elevations takes longer than at lower elevation because of the lower boiling temperature. Once water begins to boil, its temperature remains constant as the energy from the heating is used to convert the liquid water to water vapor. For example, water boils at 95 degrees Celsius, 203 degrees Fahrenheit, in Denver, which is about 5,000 feet above sea level.

They seem to be stuck on Denver... :undecided Ya readin' this, soy327?

...ANYWAY...

Around HERE, it pretty much boils at 212°F.

If one DOES attempt to calibrate a thermometer by immersing it into water at a rolling boil, first consult the site above to check the actual temperature that water boils in YOUR neck of the woods, at that particular point on a time/space continuum, 'cause your mileage may vary - a lot more than mine does. :D

Originally Posted by Judy, USMC

I've found that pinpoint accuracy is not a necessity

I agree - a couple of degrees one way or the other will probably not cause even a minor explosion, but I have found when pouring soy wax, 10-15° can make quite a difference in the finished product... depending on the particular soy wax (not to mention the dew point, air currents in the room, ambient air temperature, caloric intake of the chandler and phase of the moon...). It also becomes more critical if one suddenly begins having problems (or has never stopped having them) with their candles...

Now I know out in the world they make real sophisticated laboratory-grade temperature measuring devices, and if I were testing the properties of soy wax candles for a living, I'd surely want the best equipment someone else's money could buy; but what I'm looking for here is to try to ascertain whether the added expense of a more accurate instrument is justifiable over the long haul for the home chandler. I, too, would rather spend my money on FOs instead of equipment, unless that equipment will help me save money with fewer screwups and more consistent quality control...

From the replies I've read thus far, it sounds like one of those laser thingys would be novel to have around for checking melt pool temps & stuff like that, and the digital probes look pretty cool, especially if they will alert a space case like me when the melter has reached critical mass, but to be able to keep a thermometer in every pour pot & melter, something less expensive seems to serve many folks well...

Originally Posted by EricofAz

If you try and it looks close, go for it!

Are you suggesting that under certain circumstances one should fly IFR? :laugh2:

Originally Posted by soy327

Let's see if Stella taught me how to do this right:laugh2::laugh2:

I may live to regret that post... no good deed goes unpunished...:laugh2::laugh2::laugh2: Edited by Stella1952
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