<$100 dabbing thermometer?

[ragnorokk]

Hey guys, I found my laser thermometer may be good for telling me the temp of a wort kettle from across the room, but it can't accurately gauge something small like a nail. I saw there's a fluke thermometer for over $100, but I'm just looking to get an approximation of temp (+/- 10degrees?) for my wax pens and banger (science, boyee). Any suggestions from the FC front lines?

 

[OF]

I'm afraid you're fighting a loosing battle. Pyrometers (optical thermometers, using IR) are basically light meters. So you need a spot version (rare, but around in the semiconductor/electronics world), which generally must be used at an exact distance. Mine 'sees' a .1 inch diameter spot, but has to be exactly .5 inches out.

Laser has noting to do with it, it's there as an aiming aid only. My spot version uses two lasers to control the distance. It's possible to use a normal 'wide view' one (like you no doubt have) using a lens to refocus the field of view. It takes some fiddling against a hot target to focus, but it can be done.

However, the big issue against you is "emissivity". How bright (in relative terms) does that material glow. That is 'how much does it stand out'. This varies a LOT with materials and temperatures when the temperature differences start getting bigger (like reading a vape pen). You can be hundreds of degrees off, easily.

Relative readings are fairly easy, and often useful, but absolute ones not so.

http://www.omega.com/temperature/z/pdf/z057-058.pdf
http://support.fluke.com/raytek-sales/Download/Asset/IR_THEORY_55514_ENG_REVB_LR.PDF

Sorry, I'm sure that was not the answer you were looking for, but it's the way they work.

OF

 

[ragnorokk]

I'm afraid you're fighting a loosing battle. Pyrometers (optical thermometers, using IR) are basically light meters. So you need a spot version (rare, but around in the semiconductor/electronics world), which generally must be used at an exact distance. Mine 'sees' a .1 inch diameter spot, but has to be exactly .5 inches out.

Laser has noting to do with it, it's there as an aiming aid only. My spot version uses two lasers to control the distance. It's possible to use a normal 'wide view' one (like you no doubt have) using a lens to refocus the field of view. It takes some fiddling against a hot target to focus, but it can be done.

However, the big issue against you is "emissivity". How bright (in relative terms) does that material glow. That is 'how much does it stand out'. This varies a LOT with materials and temperatures when the temperature differences start getting bigger (like reading a vape pen). You can be hundreds of degrees off, easily.

Relative readings are fairly easy, and often useful, but absolute ones not so.

http://www.omega.com/temperature/z/pdf/z057-058.pdf
http://support.fluke.com/raytek-sales/Download/Asset/IR_THEORY_55514_ENG_REVB_LR.PDF

Sorry, I'm sure that was not the answer you were looking for, but it's the way they work.

OF

I was hoping for information about a cheap thermocouple-using thermometer, since the IR unit won't work for my purposes, but I appreciate the explanation of why it won't work.

 

[h3rbalist]

I struggled with temp guns.

Gave up in the end and will just get an enail.

(when I can afford one)

What happened to your avatar?

 

[Joel W.]

For wax pens, there are few mod boxes (evic, sx mini, excetra) now have temp control options. Some of which will work on wax pens atomizers and give you temp measurements based on wire resistance changes that work really well. These may not be real super accurate temps but they give you a reference point for adjustment to fine tune the vapor.

 

[ragnorokk]

For wax pens, there are few mod boxes (evic, sx mini, excetra) now have temp control options. Some of which will work on wax pens atomizers and give you temp measurements based on wire resistance changes that work really well. These may not be real super accurate temps but they give you a reference point for adjustment to fine tune the vapor.

True, though I'm waiting until that's out of its infancy and more "universal" temp control (ceramic, Ti, ni) units hit the market. It's great that I can throttle my pen, I'd just like the accuracy of proper algorithms for my ceramic elements (as well as everything else)

 

[jon-no-h]

@ragnorokk We use these thermometers, they work really good. only problem is they read in Celsius, which is pretty easy to convert.

 

[Joel W.]

I'm waiting until that's out of its infancy and more "universal" temp control (ceramic, Ti, ni) units hit the market.

Mini invader seems to work well with ceramic ,ti and ni also.

 

[ragnorokk]

Mini invader seems to work well with ceramic ,ti and ni also.

It doesn't know Ti/ceramic, right, you just dial it in?

 

[Joel W.]

It doesn't know Ti/ceramic, right, you just dial it in?

I have not used it but read on their site that it lists Ti and Ni wire, but the group in the divine tribe thread seems to be having good luck with it on the ceramic donut?

I think I've seen your post in there now and again.

I have only tried the IPV4 and the Evic and neither like ceramic rods or donuts in temp mode

 

[ragnorokk]

I have not used it but read on their site that it lists Ti and Ni wire, but the group in the divine tribe thread seems to be having good luck with it on the ceramic donut?

I think I've seen your post in there now and again.

I have only tried the IPV4 and the Evic and neither like ceramic rods or donuts in temp mode

Ah. Yeah, they're all using stuff designed for ni and just adjusting based on experience, and noting what "false" temp they like it at -- it's nice that it keeps people from burning their load, tho.

 

[OF]

I was hoping for information about a cheap thermocouple-using thermometer, since the IR unit won't work for my purposes, but I appreciate the explanation of why it won't work.

That's a whole different question, with a new set of limitations. As another posted says K type T/C gauges are common and potentially useful. The problem with them here is one of thermodynamics. There's sure to be losses (heat wise) from contact unless you spot weld the leads on and use very fine wire. Pretty much not possible with vape pens I think? The issue is the leads sink heat away so are actually cooler than the spot being probed, even with solid physical contact.

There's a wide spread misconception with T/Cs that the signal is generated 'at the junction'. That clearly can't be so since they are welded together.

Rather the signal is developed in the leads (the wires themselves) as the cool on the run back to the controller ('meter'). In critical applications with long runs this is often taken advantage of by using very high grade wire 'up close' where most of the heat drop happens and lower grade (same material, not as pure and much cheaper) for the bulk of the run. If there's a temperature drop between the hot part and the junction (due to heat flow and less than perfect contact) that will be a fixed offset (too low a reading).

For reading vape pens and other stuff you can't weld to best to try something else I think?

OF

 

[ragnorokk]

That's a whole different question, with a new set of limitations. As another posted says K type T/C gauges are common and potentially useful. The problem with them here is one of thermodynamics. There's sure to be losses (heat wise) from contact unless you spot weld the leads on and use very fine wire. Pretty much not possible with vape pens I think? The issue is the leads sink heat away so are actually cooler than the spot being probed, even with solid physical contact.

There's a wide spread misconception with T/Cs that the signal is generated 'at the junction'. That clearly can't be so since they are welded together.

Rather the signal is developed in the leads (the wires themselves) as the cool on the run back to the controller ('meter'). In critical applications with long runs this is often taken advantage of by using very high grade wire 'up close' where most of the heat drop happens and lower grade (same material, not as pure and much cheaper) for the bulk of the run. If there's a temperature drop between the hot part and the junction (due to heat flow and less than perfect contact) that will be a fixed offset (too low a reading).

For reading vape pens and other stuff you can't weld to best to try something else I think?

OF

Yeah, probably best not to weld, unless I decide I like inhaling some tasty rosin-core solder. Lip smacking good. Thx for the tip; How wildly innacurate do you think readings would be with a k-type thermocouple? Also, could I just replace the wire with something better for improved results?

 

[OF]

Yeah, probably best not to weld, unless I decide I like inhaling some tasty rosin-core solder. Lip smacking good. Thx for the tip; How wildly innacurate do you think readings would be with a k-type thermocouple? Also, could I just replace the wire with something better for improved results?

Welding is not soldering. Spot welding needs no flux usually, and doesn't add Lead (it uses a burst of current to locally heat the metals to melt and fuse them at that point. Plenty safe, but very hard to do on such tiny wires (the two leads need to connect to the exact same spot or heater current will foul it up.

It's a heat flow issue, not the quality of the wire (which as I tried to explain really only matters where the temperatures are changing (one end of the wire hotter than the other). As a guess you might get 40 or 50 degrees difference test to test? Maybe more. More importantly I think the 'window' of variation is going to be wider than the temperature changes you're tying to track?

Not an easy job, but I don't think T/Cs are the answer. There's a lot good information on this good stuff from Omega Engineering, the big dog in T/Cs. It used to be in a four or 5 inch thick 'handbook', now I'm sure it's on line.

OF

 

[ragnorokk]

Well, I can't spot weld at home, so I'd be soldering... Except I wont be

Thx for the hot tip on temp variance, I'd seen tc's used to "scientifically verify" temps here on FC, so I assumed that was legit.