TC beyond Ni200: Nickel Purity, Dicodes; Ti, SS, Resistherm NiFe30; Coefficient of Resistance
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The two wires are two different alloys and an EMF is created at the welded junction which is proportional to temperature and the composition of the two wires. The box just measures the EMF created and displays the corresponding temperature.
duane
Right, sorry - the cold junction is in the device itself, the reference temperature against which the probe (the 'hot junction') is compared.
The UNI-T has a NTC (Negative Temperature Coefficient) temperature sensor (thermristor) internally which it compares to the probe to determine the probe temp as an offset of real temp. There's ventilation holes for the NTC in the top of the device.
The review of the device I read says it has a setting to disable the internal NTC: " turn off the cold junction temperature compensation(turn off NTC)," Does that mean it would show the temperature offset only? Ie if current ambient temperature is 20°C and the device was showing 200°C with NTC on, would it show 180°C with NTC off?
The UNI-T has a NTC (Negative Temperature Coefficient) temperature sensor (thermristor) internally which it compares to the probe to determine the probe temp as an offset of real temp. There's ventilation holes for the NTC in the top of the device.
The review of the device I read says it has a setting to disable the internal NTC: " turn off the cold junction temperature compensation(turn off NTC)," Does that mean it would show the temperature offset only? Ie if current ambient temperature is 20°C and the device was showing 200°C with NTC on, would it show 180°C with NTC off?
I'm not familiar with that specific device so I can't comment on its internal function. My assumption was that it's a conventional device for use with a thermocouple as the bare wire photo you showed. Haven't read the review of the device yet.
Duane
Just read over the review...seems to be a completely conventional TC device albeit a real bargain if it performs as stated. I'm not sure of the accuracy at higher temperatures since it seems to be focused on temps that don't start fires...but it can't be that bad. I bet it's a lot better than the Fasttech device. 
Duane
Duane
I'm not sure why one would want to turn off the cold junction compensation. Wikipedia has a sort of primer on TCs maybe something in there would explain why turning off the compensation would be done.
Thermocouple - Wikipedia, the free encyclopedia
Duane
Thermocouple - Wikipedia, the free encyclopedia
Duane
Thanks! Yeah, the stated accuracy is 0.2% + 0..6°C - I don't know if that means it could be up to 6°C at any time, or whether it's an increasing inaccuracy as the temperature increases?
In the worst case that would mean at 250°C it would be at most 6.5°C out. But less if the 0..6 increases throughout the range - maybe a max of 2.5°C up to 250°C.
I'm not quite sure if those accuracy guarantees are for the whole range or just part of it? The reviewer seemed to suggest part, but the documentation just says it's valid for ambient temps up to 28°C and "operating temperature" up to 50°C - but surely operating temp means of the device itself, not actually what you're measuring? Or are they saying they're only guaranteeing those accuracy stats up to 50°C measurement?
Anyway, even a 10°C margin of error up to 300°C is going to be acceptable, and I'm hoping it will be accurate to at least within 5°C at that level - which is the minimum margin of error for TC anyway.
In the worst case that would mean at 250°C it would be at most 6.5°C out. But less if the 0..6 increases throughout the range - maybe a max of 2.5°C up to 250°C.
I'm not quite sure if those accuracy guarantees are for the whole range or just part of it? The reviewer seemed to suggest part, but the documentation just says it's valid for ambient temps up to 28°C and "operating temperature" up to 50°C - but surely operating temp means of the device itself, not actually what you're measuring? Or are they saying they're only guaranteeing those accuracy stats up to 50°C measurement?
Anyway, even a 10°C margin of error up to 300°C is going to be acceptable, and I'm hoping it will be accurate to at least within 5°C at that level - which is the minimum margin of error for TC anyway.
My guess would be that the accuracy will decrease as the temperature increases but you should be able to get an idea what the inaccuracy will be by doing the water thing with the tc in the coil at the same time and then just plain guessing about the next 100C. I'd think if you do this you'd have a pretty good idea of what is going on in the coil at 200C.
I don't know that we really care about a few degrees one way or the other or that we would be able to discern an effect of a few degrees anyway.
Duane
I think a light bulb just went on....I think you would want to turn off the internal cold junction if you were setting up an "ice junction" as described in the Wikipedia thing. That would be overkill (and a pain in the backside) I think. At least my very tired brain is functioning a little even if it's too late here.
You are either up early...or a confirmed insomniac.
Off to bed.
Duane
You are either up early...or a confirmed insomniac.
Off to bed.
Duane
I am never up early, only ever late Going to bed too now. (I tend to have a 1-2 hour nap either around 4pm or 8pm, then stay up until 4am at least and get up at 10 or so. Today I had thermocouples to research and buy, so it's become 7.30am. I'll get up maybe 12.30.)
Thanks for all the info!
Going to bed too now. (I tend to have a 1-2 hour nap either around 4pm or 8pm, then stay up until 4am at least and get up at 10 or so. Today I had thermocouples to research and buy, so it's become 7.30am. I'll get up maybe 12.30.)Thanks for all the info!
I want your job... I'm dragging myself out of my bed right now and I want to sleep lol.I am never up early, only ever late
Thanks for all the info!
Regards
Tony
Sent from my keyboard through my phone or something like that.
i been following the multiple threads and I wanna say thanks to you guys, great work you doing here for the community ^^ also may I ask about stainless steel coils TheBloke, do you feel its ''The next big thing'' ? i like the idea and have a sxk flask on the way
Actually I am going to get these probes as well. They're made by a UK company, saying the following:
This is one of the smallest wire gauge thermocouples available just 0.13mm diameter these are manufactured in our UK factory using Omega TT-KI-36 wire class1 with a max temperature of 260°c, they are welded using an argon gas to stop any oxidisation and create the best weld possible.With a response time of 1 second in air makes this thermocouple ideal for applications like biophysics, medical research,gas chromatography etc.
This sounds pretty interesting - 1 second response time is obviously helpful; the standard probes like the ones I showed in above post don't mention a response time. I also like how it's a very thin, small probe at the end, allowing for precise positioning on a part of a coil.
They're max 260°C so I'd need to use the standard probes first to verify I'm within that range, but any normal TC testing would be anyway.
I'm also wondering whether it would be possible to strip back a bit more of the two wires, and create a probe that curls round inside the coil, matching the turns of the coil itself! So having a coiled temp sensor in the exact same shape as the coil, 0.5mm inside the main coil (or as close I could manage.)
Because these guys are in the UK I should be able to ask them about that - maybe they'd even make me a set.
@Quantum Mech @funkyrudi @balazsk @druckle you guys probably know about this stuff - thoughts?
I was thinking about getting as small as possible 'touch probe'
Hoping then it can be held on the centre wrap of a spaced coil without shorting across the coils
Have tried with insertion probe without success mate, shorting
And not sure insulating a probe will give a true reading ie: with cotton / rayon
With them holding liquid they will give a 'wet bulb' reading rather than a truer 'dry bulb' reading this can be several degree's different depending on liquid used
Just like the water test it holds the coil at its boiling point
I am not sure & will need to check but that could just be there lingo for switching to & from NTC to PT1000/PT200 probes
OK good to know, thanks.
Can you tell me more about touch probes? Are they a different type? Like can a K Probe be a touch probe or is a touch probe a different probe type - like type J, T, E, R, S, or N?
What material are they usually made of - if you think they might not short presumably they are, or can be, non metallic? Or at least non-conductive?
I really like Stainless Steel. I think it is definitely part of the "next big thing", where "the next big thing" is "anything other than Ni200". Ni200 is dead to me. I can't think of a single reason to use it again now I have discovered Titanium, Resistherm and Stainless Steel.
Ni200's only advantage is that its TCR is the highest, meaning it is theoretically the most accurate. Dicodes quote Ni200 as being accurate to nearest 5°C / 10°F, where Stainless Steel is accurate only to nearest 30°C / 86°F; Titanium and Resistherm they don't mention accuracy figures for, but will be somewhere in between, let's say nearest 10°C / 50°F.
However, given that even Stainless Steel with its minimal accuracy can be a very satisfying and reliable TC vape, we can see that absolute accuracy is not essential. As Dicodes put it, what is essential is repeatability. In other words, the most important thing is that we can find a setting that gives a good vape - good flavour, right quantity and consistency and temperature of vapour, no dry hits - and then we can repeat it every time. This is achievable with Stainless Steel, despite its low on-paper accuracy.
All three of the Beyond Ni200 wires have several major advantages over Ni200:
- They have higher base resistances
- requiring lower wattage, lower amp draw, lower voltage drop and thus less battery usage and longer battery life
- more easily enabling dual (or even quad) coil builds
- and more easily enabling the use of thicker and/or twisted wires
- They can be used as contact coils, or near-contact coils, without shorting
- Contact (micro) coils are said to be more efficient at heating
- They are also shorter, making it much easier to fit builds into many atomizers - this fact also combines with point 1, higher base resistance; Ni200 coils not only have to be spaced, they also have such low resistance that they tend to need to be longer too, especially with thicker wires; some of my atomizers just don't have the room for many spaced Ni200 builds - or it is great trouble making them fit.
- Plus one does not want a coil to extend far outside the size of the airhole - otherwise only part of the coil will be aired and cooled, lowering the accuracy of TC and perhaps affecting flavour
- Even if one does not want a contact coil, it is beneficial to not have to worry if a given coil is precisely spaced - I used to spend ages checking my Ni200 builds, especially checking again after wicking, to be sure no part was touching another part.
- They are generally stronger and less likely to break when tightened down and when having adjustments made/wicks inserted
- Many people find they taste better - that they can detect unpleasant 'nickel flavours' in Ni200 where they can taste nothing unwanted in Beyond Ni200 wires
- In the case of SS and Resistherm, they can be pulsed like Kanthal to remove hot spots and ensure a great performing, consistent, glowing-inside-out coil that will vape as well as a Kanthal coil but for TC as well.
So yes, to answer your original question, I do think Stainless is part of the next big thing for sure.
What i still can't decide is the relative rankings of these three wires - SS, Ti, Resi. Which do I prefer? So far I have spread my time between all three, and cannot yet answer. They all have advantages and disadvantages compared to each other.
I will say that SS' adoption will be hampered by the fact it is not usable no legacy TC devices. One can take a Resistherm or Titanium build and vape it on any existing TC device, as long as one lowers the target temperature - about 90-100°F on DNA 40 devices, 140-170°F on other devices. With this lowering of target temp, the difference in TCR is accounted for and both Titanium and Resitherm vape pretty well on any existing TC device.
That is not true for SS, whose TCR is so low it is not hugely usable on legacy devices. It does work, to some extent - but it will also burn dry cotton and so there's always a risk of dry/burnt hits; the temperature offset required is too extreme.
For that reason it's possible that SS will never catch on enough to be a huge hit - those who go beyond Ni200 are more likely to go to Titanium, which is already gaining traction. Ditto Resistherm, while in some ways better perofrming than Titanium, will be hampered by its high initial cost and the fact that only Dicodes - who are relatively unknown outside Germany I would say - are promoting it.
One thing to consider is that this TCR-adjusting variant of resistance-based TC is not necessarily going to be the way of the long term future. With Innokin's innovations into tanks with sensors in them, requiring special devices and probably not allowing rebuildable coils at first but ultimately promising accurate use of any wire type, perhaps resistance-based TC is not going to last. TCR adjustment might be a short term evolution to a long-term dead end technology, rather than the future of TC itself. If that's the case, I doubt SS will get much traction because it's only when TCR adjusting mods are more standard that its adoption will greatly rise.
But we will see. For certain, once you have your SXK mod I highly recommend you get some SS316 or SS317 - it's cheap, effective, and well worth trying out as a comparison to the others.
Thank you for all this valuable information, I for sure will try SS once I receive the flask, and if I understand right, if sensors are going to get mainstream, this would probably mean we can use whatever wire we wish once they come out with a rta version, so many nice things to come ^^
i dont regret the ggts/510 atomizers days, thats for sure
i dont regret the ggts/510 atomizers days, thats for sure
GGTS seems so long ago but was just a short time. A very sturdy socket.
Just in case some of the newer members aren't familiar with GGTS, This is a clone of the GGTS made by Rainbow called MKB-TS. It's one of the first "high quality" cloned mods.
(picture taken today)
Just in case some of the newer members aren't familiar with GGTS, This is a clone of the GGTS made by Rainbow called MKB-TS. It's one of the first "high quality" cloned mods.
(picture taken today)
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nice looking clone, top it with an old school *UFC* tank clone and its good to go ( on a shelf )
Yeah absolutely, of course you're right - SS could grow in popularity when any wire is possible. In fact that is when it will come into its own, because then its low TCR won't matter at all.
What I wonder is how many bother with it when just plain Kanthal works. It does have advantages over Kanthal - people were starting to try it even before TC, as an alternative to Kanthal. But Kanthal has such a vast following it will probably remain king if it works well for sensor-TC.
But yes, new connectors / backwards compatibility issues could definitely harm adoption. I hope Innokin are working on an adapter so any 510 atty can work on their mod in normal TC mode (resistance not sensor), that will help adoption a lot.
Thanks! I had no idea what GGTS was. Why did it lose out to 510? Where does the mod end and atty begin in that photo? Is the coil somewhere between the silver knurled ring and the brass ring?
I will not mourn the loss of the 510 socket. It cause so many problems, so many inconveniences - the whole craziness with fixed vs sprung pin, attys not going flush, 510s so easy to damage and so easy to get stuck with over-tightening, or poor connections from under-tightening. I so much wish we had some kind of push-fit socket, maybe a single turn of fixed amount to lock. Even something like a bayonet lightbulb socket seems preferable - push in against standard spring, turn by 90°, done.
I'm sure the 510 seemed like a reasonable solution at the time and was never envisaged doing all it does now - as usually happens with quick solutions: "nothing is as permanent as a temporary solution."
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