TC beyond Ni200: Nickel Purity, Dicodes; Ti, SS, Resistherm NiFe30; Coefficient of Resistance

[IanDVaypes]

You're resistance problems is not with the spring loaded 510. The squape r has a weak point in the adjustable 510 pin. From the very start, I had jumping resistance with the squape r using ni200. I stuffed a few strands of silicone wire in the threads and bam, no problems ever again. Any atty that is adjustable in the 510 via threads is going to be very inconsistent. Sure you might vape just fine in the beginning but ejuice gets into the threads and throws the resistance way off.

After I fixed the issue, the squape r will read the exact same for every mod. Vaporshark, fatdaddy dna 40 mods, sx mini and even fixed 510s. Now that I have the dna 40 in my wizard, it reads the same there too.

 

[funkyrudi]

another example
Ni Coil 0.1 Ohm, K4 static resistance 0.04 Ohm at 232C
316.8C = 85C too much

not bad :-(

 

[TheBloke]

Wrong calculation

When we have a 0,4 Ohm coil and a static resistance of 0,04 Ohm and a set temperature of 232 C, the chip will expect a value of 0.76648 Ohm. But this value contains the static resistance, so we have a coil resistance of 0.72648 and the coil temperature will be 253.2C = 21C too much.
With the static resistance of 0.003 Ohm we would get 227.16C at the coil. This seems strange because in the first case the coil temperature increases and in the second case decreases. But I guess that`s right.

Ah you have a point! I forgot to allow for the static resistance in the final temp calculation.

But I don't think it has the effect you said exactly. Edit: or rather, if it does, then that's a different calc than the one I was doing, I haven't done the calc the way round you're doing it.

Firstly, I disregard the 0.76648 value because it is only for interest - it is the value the chip expects to see, but actually it never sees it. Maybe I confused things by including that calculation at all.

I think this is the calc?

• If the mod reads the coil as 0.44 then it expects 0.76648 (Mod's expected rise for 232 = 0.76648) = only FYI not important to accuracy calculation
• But in fact the coil is 0.40 so at 232 it will actually rise to 0.6968 (Real coil rise = 0.6968)
• The mod will see 0.6968 as 0.7368 (= real rise + 0.04 static resistance)
• It will detect 0.7368 on a 0.44 coil as 212.7°C
• So when the coil is at 232 it will detect it as 212.7 = 20°C too low. Not 45°C as I said before

Agreed? If so I will edit this back in to earlier posts.

Well spotted!

 

[funkyrudi]

You're resistance problems is not with the spring loaded 510. The squape r has a weak point in the adjustable 510 pin. From the very start, I had jumping resistance with the squape r using ni200. I stuffed a few strands of silicone wire in the threads and bam, no problems ever again. Any atty that is adjustable in the 510 via threads is going to be very inconsistent. Sure you might vape just fine in the beginning but ejuice gets into the threads and throws the resistance way off.

After I fixed the issue, the squape r will read the exact same for every mod. Vaporshark, fatdaddy dna 40 mods, sx mini and even fixed 510s. Now that I have the dna 40 in my wizard, it reads the same there too.

The spring is the biggest problem, the next problems are the threads for the LC, because that`s the minus conection and the 510 screw is a minor problem, because it is force fitted.

The Squape is different and doesn`t have a force fitted 510 screw, but you can make it force fitted

 

[funkyrudi]

Ah you have a point! I forgot to allow for the static resistance in the final temp calculation.

But I don't think it has the effect you said exactly. In fact the discrepancy is less than you said even, and much less than I said.

Firstly, I disregard the 0.76648 value because it is only for interest - it is the value the chip expects to see, but actually it never sees it. Maybe I confused things by including that calculation at all.

I think this is the calc?

• If the mod reads the coil as 0.44 then it expects 0.76648 (Mod's expected rise for 232 = 0.76648) = only FYI not important to accuracy calculation
• But in fact the coil is 0.40 so at 232 it will actually rise to 0.6968 (Real coil rise = 0.6968)
• The mod will see 0.6968 as 0.7368 (= real rise + 0.04 static resistance)
• It will detect 0.7368 on a 0.44 coil as 212.7°C
• So when the coil is at 232 it will detect it as 212.7 = under 10°C too low. Not 45°C as I said before

Agreed? If so I will edit this back in to earlier posts.

Well spotted!

No, sorry, I can not agree.

The chipset expects 0.76648 Ohm to reach the 232C. When he reads this value, it is a sum of 0.04 Ohm static R and 0.72648 Ohm coil resistance. And with this coil resistance you can calculate the temp for the 0.40 coil = 253.19999999999996C

 

[TheBloke]

No, sorry, I can not agree.

The chipset expects 0.76648 Ohm to reach the 232C. When he reads this value, it is a sum of 0.04 Ohm static R and 0.72648 Ohm coil resistance. And with this coil resistance you can calculate the temp for the 0.40 coil = 253.19999999999996C

Yes you're right, it's just two ways of doing the same calc - either calculating what resistance will be seen by the mod when the coil is actually at 232 (my calc), or calculating the temperature when the resistance actually reads the expected resistance for 232 and the coil is higher (your calc)

Edit no I'm confused hang on let me put your numbers in the calc

 

[TheBloke]

I am getting a bit confused in all the numbers now

This is the way round I do the calculation. I see your point about when it reaches 0.76648 that is 0.7268 which is 253 but the way I do the calc, it never reaches 0.76648 because that's calculating for a different target than 232.

Can you explain where you think this is wrong?

1. The real coil is 0.40
   1. RC = 0.40
2. The coil is read by mod as 0.44
   1. MC = 0.44
3. MC with target temp 232 gives 0.76648
   1. MCTT = 0.76648
4. But RC target temp 232 is 0.6968
   1. RCTT = 0.6968
5. The actual coil temp is 232
   1. Temp = 232
6. Therefore the coil heats to RCTT, but the mod sees this with static resistance added +0.04
   1. MRCTT = 0.6968 + 0.04 = 0.7368
7. MRCTT calculated for MC (0.44) gives Mod Predicted Temp of 212.7°C
8. But the actual Temp is 232, an inaccuracy of -19.3°

You can see I am not using MCTT except for reference, because I think that when the actual temp is 232, it will only reach RCTT which will display as MRCTT, both of which are lower.

Wait, aren't we just talking about the same damn thing?

It would only actually show MCTT when the real coil temp is 253. When RC reaches 253 the real resistance will be 0.72648 which displays as 0.76648 which the mod thinks is 232 for a 0.44 start..

So:
At real temp 232, it detects 212.7 = -19.3
At real temp 253, it detects 232 = -21

They are both right and consistent! I told you we were just doing the same calc in two different ways, with two different target temps

 

[funkyrudi]

You can forget 4. the RC target temp, we don`t need this for this calculation.
You have your 0.4 coil and want to heat it up to 232, but your atty has an static resistance of 0,04 Ohm. The total resistance ist 0,44 Ohm and the chipset reads 0,44 ohms and expects a Ohm value of 0.76648 Ohm for reaching the set temp. Part of this estimated ohm value is the static resistance, which doesn`t heat up nor changes his value. When we reach the estimated 0.76648 Ohm, the coil will have 0,72648 Ohm only. This value is equivalent to a temperature - like a temp sensor for temperature meter.

It´s late in Europe - talk to you tomorrow

My calculation has a too high temp
and your calculation a too low temp

What had you expected?
Good night

 

[TheBloke]

You can forget 4. the RC target temp, we don`t need this for this calculation.
You have your 0.4 coil and want to heat it up to 232, but your atty has an static resistance of 0,04 Ohm. The total resistance ist 0,44 Ohm and the chipset reads 0,44 ohms and expects a Ohm value of 0.76648 Ohm for reaching the set temp. Part of this estimated ohm value is the static resistance, which doesn`t heat up nor changes his value. When we reach the estimated 0.76648 Ohm, the coil will have 0,72648 Ohm only. This value is equivalent to a temperature - like a temp sensor for temperature meter

Check my edit if you didn't already - we are both doing the same calc. You are ignoring my number 4, I am ignoring your 253. We are calculating for different real temperatures.

You are calculating for the mod's estimated 232, which is actually 253
I am calculating for the real 232, which the mod estimates is 212.7

We are both doing the same calculation, just a different way around. In both cases the difference is that the mod predicts the temp as 20°C lower than it really is. The inaccuracy is ~ -20°C (-21 at your target temp, -19.3 at mine)

 

[TheBloke]

It´s late in Europe - talk to you tomorrow

My calculation has a too high temp
and your calculation a too low temp

What had you expected?
Good night

I am in Europe too (but one hour behind you I admit )

Think about it in the morning and get back to me. I am certain we are doing the same thing in a different way. You are just thinking about it in the opposite point of view and thinking you are getting a different value.

We both show an inaccuracy in the mod that is too low. The mod predicts the temperature is lower than it really is.

Do your calculation again, but work out what the mod will say when the real temperature of the 0.40 coil is 232°. So if you put a super accurate thermometer on the coil, and it reads 232, what will the mod think the temp is? I say 212.7, because the mod has an inaccuracy at this level of -19.3°.

 

[TheBloke]

I think the key area of confusion is:

My calculation has a too high temp
and your calculation a too low temp

You think this because we are expressing the same thing in different ways.

What is 'too high'? What is 'too low'? We are using different definitions of 'what'.

I am saying that the estimated temp is lower than the actual temp.
You are saying the actual temp is higher than the estimated temp.

Two ways of saying exactly the same thing.

The chipset expects 0.76648 Ohm to reach the 232C. When he reads this value, it is a sum of 0.04 Ohm static R and 0.72648 Ohm coil resistance. And with this coil resistance you can calculate the temp for the 0.40 coil = 253.19999999999996C

This is correct. In your example here, estimated = 232; actual = 253. The mod (estimated) is too low.

This is exactly the same as my example: actual = 232; estimated = 212.7. The mod (estimated) is too low.

 

[IML8]

They're likely all correct for the specific sample they were testing.

Yes, there are varying grades of Nickel used in electronics that are all 99.5% pure, but nevertheless have differing conductance and TCRs. .006 is commonly used as the alpha constant (TCR) when the specific grade isn't mentioned (various electronics components e.g., RTD sensors et al), but everything I've seen where Ni 200 is particularly specified the TCR is listed as .004

Maybe I just haven't seen the definitive guide yet though.

 

[soulseek]

I have to say I am finding it extremely difficult to resist buying a Dicodes. The lack of thermometer is annoying in principle but seems pretty irrelevant most of the time - it's almost a constant 20°C in my office/study in any case (where I spend 90% of my time). And even when temperatures will vary, 10° up or down is well within the margin of error for any atty anyway, even assuming that one forgets to adjust for it.

In some respects it's even a benefit - the thermometer is only used to get the base temperature of an atty. If the mod is hot it can't be immediately re-used on a cold atty, where the Dicodes could. I'm thinking probably these disadvantages/advantages might balance out in the long run.

@ndb70 @soulseek you've both described various aspects of it, but can you give your overall view?

It would be the most expensive mod I'd ever bought, so I'd really be doing so as a kind of quality benchmark for TC, ohms reading, coefficient adjustments. So for example, to do a check that my calculations of Nickel Purity's scale are accurate by comparing them to the Dicodes.

And to actually vape on, of course But I can't justify the cost for that alone; I could buy four NP mods for the cost of one Dicodes, or five if I go for the 2380.

@ndb70 in particular, you've done a lot of testing it seems - are you happy with it as a 'benchmark' mod (manual thermometer calcs aside)?

I think the dicodes is a solid device. I still haven't received my Ti, so I can't comment 100% on the temp control (since I won't be using it permantenly with the Resistherm wire) but so far I'm more than satisfied. I think the ability to adjust to the ambient temperature would have been a nice addition but it doesn't make-or-break the device. However, I am planning on trying other devices as welL; I think this is an area of e-cigs that will see rapid development in the years to come.

 

[TheotherSteveS]

I think the key area of confusion is:

My calculation has a too high temp
and your calculation a too low temp

You think this because we are expressing the same thing in different ways.

What is 'too high'? What is 'too low'? We are using different definitions of 'what'.

I am saying that the estimated temp is lower than the actual temp.
You are saying the actual temp is higher than the estimated temp.

Two ways of saying exactly the same thing.



This is correct. In your example here, estimated = 232; actual = 253. The mod (estimated) is too low.

This is exactly the same as my example: actual = 232; estimated = 212.7. The mod (estimated) is too low.

i guess the static resistance wont change on firing as the atty etc temp shouldnt change much...

 

[funkyrudi]

@TheBloke
I got you

We were following two different goals. You calculated the temperature setting for getting a coil temperature of 232C and I calculated the actual coil temperature for a TC setting of 232C.

Your right, we are both right, but I didn´t check what you did, sorry - it was late and all these numbers ;-)

Your calculation is more interesting for the daily use - mine was only interesting for showing how much we miss the target temperature ( that`s what we came from earlier )

 

[TheBloke]

i guess the static resistance wont change on firing as the atty etc temp shouldnt change much...

Yeah that's what we're assuming - that, in our example above, static resistance is a constant 0.04 throughout. It affects the starting resistance reading by +0.04 and it affects the end/ongoing resistance reading by +0.04.

It's that latter part that I originally forgot to include and funkyrudi spotted, which made me think the inaccuracy was greater than it was (I had 45°C, it's actually around 20°C.)

@TheBloke
I got you

We were following two different goals. You calculated the temperature setting for getting a coil temperature of 232C and I calculated the actual coil temperature for a TC setting of 232C.

Your right, we are both right, but I didn´t check what you did, sorry - it was late and all these numbers ;-)

Your calculation is more interesting for the daily use - mine was only interesting for showing how much we miss the target temperature ( that`s what we came from earlier )

Awesome Yeah it was very late and I kept getting lost as well; I am not a natural numbers/maths person! Anyway it was very useful to keep doing the calcs, now I think we both know them off by heart!


I would like to try and measure some static resistance of my own, but I don't know which mod I will trust to do it (a reason I want the Dicodes!) I am trying to see if I can do accurate ohms readings with my DMM - it reads ohms to two decimal places but I am not sure it will be precise enough overall. Also I first need some better leads (ones with hooks/clips)

First I think I am going to try and take some readings on all my mods, comparing against known resistances (Steam Engine) using the smallest resistance path possible.

 

[ndb70]

@ndb70 can you confirm which is correct? 0.03 or 0.003?

You said 0.03 a couple of days ago, and 0.0026 today - which has the correct number of zeroes? Hundreds or thousands?

Argh! Sorry guys.
It was a late-evening-after-a-long-day post and an additional zero crept in...
0.003 is actually 0.03, 0.0026 is actually 0.026 and 0.0005 (the delta with the gold spring vs the sleeve) is actually 0.005.
I've edited the post, hope I fixed everything.
Sorry again for the confusion.

 

[TheotherSteveS]

I think the dicodes is a solid device. I still haven't received my Ti, so I can't comment 100% on the temp control (since I won't be using it permantenly with the Resistherm wire) but so far I'm more than satisfied. I think the ability to adjust to the ambient temperature would have been a nice addition but it doesn't make-or-break the device. However, I am planning on trying other devices as welL; I think this is an area of e-cigs that will see rapid development in the years to come.

Hi Soulseek
do you have the dani ex v2 or the 2380?? If the Dani, how do you find the fixed 510??

 

[TheBloke]

Argh! Sorry guys.
It was a late-evening-after-a-long-day post and an additional zero crept in...
0.003 is actually 0.03, 0.0026 is actually 0.026 and 0.0005 (the delta with the gold spring vs the sleeve) is actually 0.005.
I've edited the post, hope I fixed everything.
Sorry again for the confusion.

Awesome thanks for confirming! I do that all the time, I cannot tell you how many extra or missing zeroes I had in my first two posts before I edited it several times

OK so yes we are talking hundreds, and 0.026 is the current figure.

So great, we have a real confirmed static to work off, I will do some calcs now for various wires.

 

[ndb70]

I don`t know what´s your prefered air draw, but if you like it airy, you could use the air regulating screw # B13 to get the best conductivity on the K4. I haven`t meassured it on my Keithley 580 Microohmmeter, but I get constant values

Are you referring to the "trick" of completely unscrewing B13? If yes I tried that in the beginning of my journey with the K4, and it kind of made things a bit better, but unfortunately I'm more of a mouth-to-lung guy and don't really like too airy draws, I think I found the best solution for the K4 with the SteamTuners' "spring-udpate" sleeve and that's what I'm currently using.