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

[TheBloke]

Yeah I always forget about that, if it hovers at 100°C/212°F then it's at the right TCR - right?

I'd still do the glowing test first to get you a ballpark, that seems quicker to me because in one test - just watching the screen on the SXK - you can immediately see if it's 0.001 or 0.005 and then tune in the right range for the next tests. It'd only be inaccurate if it the TCR is massively non-linear. But I think the only wire vaguely matching that description is Ni200/Kanthal DH, that we've seen anyway. In any case at a low wattage you can get an idea of the progression of resistance and get the ballpark.

And thanks!

Actually am I being slow again - if you just soak the coil/wick, you know it's at 100/212, right? It can't go above that until the water boils?

So yeah just wet your wick (so to speak), hold down fire, and see the max resistance, and put that into the TCR calc from 20->100°C? Job done?

Edit: no not quite job done. Job done for your TCR up to 100°C, but it could differ up to 300 (I think we do see variations between 20-100 v s 20-300). But it's a start.

maybe you could do the glowing test as well, if you think you can judge the temp of a glowing coil to nerest 50°C or so. That might indicate if it's different to your 20-100 result.

 

[druckle]

I just did a "slow burn" test on the dreaded Crazy 'NiFe', heating only at 5W. I thought maybe this could be a non-linear one, so I wanted to see if all the resistance rise came at the start of the heating. Then I thought I may as well just do it properly and got the Thermo out. I didn't do my full normal test harness setup, just quickly wedged the probe between two wraps. If anything that will over-estimate the TCR (under estimate heating.)

At about 300°C the resistance rose from 0.47 to 0.60, so a TCR of around 0.00108. So, yeah. No need for proper tests I think.

(That TCR is almost identical to SS304 @ 300°C, within the margin of error of my quick test anyway. Perhaps just a coincidence.. )

Tom I think you're nailing down the coffin lid on that wire one nail at a time. Doesn't sound worth much other than twist ties on plastic bags.

Duane

 

[jazzvaper]

Well, I have an order in at Unkamen for (pure) SS 316 L but feel I need to be at a much lower awg.

So, I just placed the below order with Zivipf. They also list 23 awg but the difference of one (1-2) wrap seems insignificant to me. Want to get the ohms down from 0.5ish to 0.35 with more metal heating.


Order details:
No. Quantity Product no. Name UP VAT TP
1 1 piece(s) v4a-0.50-50m SS Wire-V4A 0.50mm / 0.020" / AWG 24
- length: 50 meter / 164 feet
11.09 € 0% 11.09 €
2 Subtotal 11.09 €
3 Delivery method Priority Delivery ( with tracking )
insured shipping with tracking information
4.99 €
4 Payment method PayPal
5 Tax area Non-EU country
6 Total amount (without VAT) 16.08 €
7 Total amount 16.08 €

 

[druckle]

Tom:

I wish I had a later version of the SXK. I know mine reads low so I should probably cross check the resistance of the coil with a dna and adjust measurement resistances I see on SXK or does that make any real difference since we're looking for delta resistance change between temp 1 and temp 2?

Duane

 

[TheBloke]

It's SS304. It has to be.

I just measured 100mm of 0.40 and 0.35. It comes out to the exact numbers predicted for SS304 on Wire Wizard. Incidentally, the spool labelled 0.32 is actually 0.35 as well

Same TCR, same resistance to three decimal places, plus same feel etc. I refuse to believe this is coincidence any more.

 

[TheBloke]

Tom:

I wish I had a later version of the SXK. I know mine reads low so I should probably cross check the resistance of the coil with a dna and adjust measurement resistances I see on SXK or does that make any real difference since we're looking for delta resistance change between temp 1 and temp 2?

Duane

Oh yeah forgot about that. Yeah delta is most important so that's probably OK.

Don't you have a DNA 200? I thought I saw you talking about one. On the 200 you can just graph it, easy peasy. If not, yeah deltas are probably enough for TCR. Well Ihope. We know the SXK's inaccuracy varies the higher up the resistance, but I think that applies only for the base reading not the live reading - else the TC would be majorly inaccurate and it isn't.

Anyway you're only going for a ballpark here, and you can tune the TCR more accurate according to the water test

 

[tchavei]

Yeah I always forget about that, if it hovers at 100°C/212°F then it's at the right TCR - right?

I thought that too until I tried titanium on a dna 40. The dna 40 doesn't have a linear built in tcr so instead of getting a reading at 79C with a Ti coil and water, I got 98C which puzzled me for days until I concluded the built in tcr couldn't be linear. Both ni 200 and titanium started almost the same but as temperatures went higher, the offset was bigger and bigger.


Regards
Tony

Sent from my keyboard through my phone or something like that.

 

[druckle]

Oh yeah forgot about that. Yeah delta is most important so that's probably OK.

Don't you have a DNA 200? I thought I saw you talking about one. On the 200 you can just graph it, easy peasy. If not, yeah deltas are probably enough for TCR. Well Ihope. We know the SXK's inaccuracy varies the higher up the resistance, but I think that applies only for the base reading not the live reading - else the TC would be majorly inaccurate and it isn't.

Anyway you're only going for a ballpark here, and you can tune the TCR more accurate according to the water test

Yes, I have a DNA 200 but it's my "precious" call is silly but what if I in my fatigued stupor set something wrong and the coil went poof? Who knows if the DNA would accept that without complaint? LOL.

Until I have a feeling I know a little bit of something about the mystery wire it's not going anywhere near my "precious"

Duane

 

[soulseek]

Tom

I'm fuzzy on this so if you can refresh me I'd appreciate it.

What's the easiest way to measure the TCR of an unknown wire? Your recommendation would be appreciated.
I have a first generation SXK flask and would like to give it a shot on a mystery wire. I looked back through our 70 pages to refresh my memory but haven't come up with the right formula.

Duane

Well assuming it has linear TCR I would guess a rough estimate could be calculated using a wick soaked in water.
Measure R of wire at rtp. Then wick it and soak it in water, fire it and measure the temperature increase.

 

[TheBloke]

I thought that too until I tried titanium on a dna 40. The dna 40 doesn't have a linear built in tcr so instead of getting a reading at 79C with a Ti coil and water, I got 98C which puzzled me for days until I concluded the built in tcr couldn't be linear. Both ni 200 and titanium started almost the same but as temperatures went higher, the offset was bigger and bigger.

Yeah true not on a DNA 40. But in principle on any single-TCR mod like the SXK.

Yes, I have a DNA 200 but it's my "precious" call is silly but what if I in my fatigued stupor set something wrong and the coil went poof? Who knows if the DNA would accept that without complaint? LOL.

Until I have a feeling I know a little bit of something about the mystery wire it's not going anywhere near my "precious"

You keep a lot of fuse wire lying around the house then?

 

[jazzvaper]

Yes, I have a DNA 200 but it's my "precious" call is silly but what if I in my fatigued stupor set something wrong and the coil went poof? Who knows if the DNA would accept that without complaint? LOL.

Until I have a feeling I know a little bit of something about the mystery wire it's not going anywhere near my "precious"

Duane

I think treating the new 'precious' with care is wise, Druckle.

Last night eScribe, or the DNA 200, would not read the actual "Temperature", only Set Temperature. This, for only one atomizer. All others read as expected.

Device vapes fine (as well as on the SX) though until I understand why I am treating is as a potential (warrantied) anomaly.

 

[TheBloke]

I think treating the new 'precious' with care is wise, Druckle.

Last night eScribe, or the DNA 200, would not read the actual "Temperature", only Set Temperature. This, for only one atomizer. All others read as expected.

Device vapes fine (as well as on the SX) though until I understand why I am treating is as a potential (warrantied) anomaly.

Ah I meant to reply to an earlier post of yours. I'm not sure if it's the same as you're describing here, but I think you posted before about resistance not rising with an SS contact coil?

If so, I've seen that before - resistance doesn't rise. It needs to be oxidised with pre-burning as a micro-coil. Then TC suddenly kicks in, and temperature rises as expected.

As I say, maybe not what you're talking about here (as you talk about only one atomizer) ,but definitely something I've seen with SS before.

 

[jazzvaper]

Ah I meant to reply to an earlier post of yours. I'm not sure if it's the same as you're describing here, but I think you posted before about resistance not rising with an SS contact coil?

If so, I've seen that before - resistance doesn't rise. It needs to be oxidised with pre-burning as a micro-coil. Then TC suddenly kicks in, and temperature rises as expected.

As I say, maybe not what you're talking about here (as you talk about only one atomizer) ,but definitely something I've seen with SS before.

No, all SS atomizers read as expected, so too the Ti. It is one Ni 200 that is not reading the Temp.

Yes, I know about dry burning the SS. As you might remember from a post above I learned that right away on the SqRs and K4 SS builds.

I tell you, though, it is a pleasure to wrap contact coils and dry burn just like Kanthal A1. Rewicked one after dry burning...consistency, ease of use, and safety all in one package. [emoji41]

 

[TheBloke]

Final conclusion on Crazy Wire "NiFe30" spools I received today: It's Stainless Steel 304

I just did my resistance readings again. Cleared all scraps of wire off my deck, to be sure I didn't measure the wrong wire or anything. Cut new wire from my Crazy wire 'NiFe' spools.

• "NiFe 0.40mm" : wire measures 0.40, 100mm measures 0.565Ω.
  • Compared to Wire Wizard, 0.40 of SS304: 5.67Ω/m = 0.567Ω for 100mm.
• "NiFe 0.35mm" : wire measures 0.35, 100mm measures 0.741Ω.
  • Compared to Wire Wizard, 0.35 of SS304: 7.41Ω/m = 0.741Ω for 100mm.
• "NiFe 0.32mm" : wire measures 0.35, same as the 0.35 spool.

As mentioned earlier, TCR at approximately 300°C came out to 0.00108 - compared to vapealone's chart for SS304: 0.001016 @ 300°C.

Writing my email to Crazy now..

Looking on the optimistic side, there's always the slight chance they sent me the wrong wire (and incorrectly labelled it NiFe30), and that therefore they really do have some NiFe there, meaning today's disappointment might be fixed.

Then again, although they do sell SS304, they don't have any listed in sizes of 0.35 or 0.40.

 

[TheBloke]

What really adds insult to injury in this whole debacle is that I got this wire on the same day that I received the 30m of SS304 I ordered separately!

So I can't even console myself with the fact that I wanted SS304 anyway, because I certainly didn't want or need 105m of it.

They'd better either send me some NiFe70/30 or refund me completely.

 

[Landman]

Received the SS430 from Unkamen today, 28ga. I'm sending some to Tom for testing, but until he puts it through the paces, I've done a tad bit of playing with it. So it is metallic and actually has a bit of spring to it. Using a coil master, it has a similar spring rate as Unkamen's Ti (measured 3.22mm off a 3mm rod). It also has about the same amount of graphite when I cleaned with IPA.

I wrapped a 6/7 coil, 3mm spaced and put it on a DNA200 which saw it as 0.74 ohms. Using a .csv @balazsk sent me to test out, I set the temp to 500/15w and put a fan on the coil. It barely turned a yellow/straw color while the temp bounced right around 500; no glow detected. After leaving it sitting for about 10 minutes, I put it in power mode, 20w. No matter how long the button was held, it stopped at 1.22 ohms, glowing nicely. I then put it at 40w and it snapped in about 3 seconds.
Next I wrapped a 5/6, 3mm contact coil for a water test. It showed .64 ohms at the start, ran a water test on it and it was stopping at 230 degrees/0.722 ohms.

 

[TheBloke]

Great thanks @Landman . Excited to try it!

So based on your 6-7 x 3mm @ 0.74Ω, that sounds very similar resistance to SS304. But we know TCR is higher, so that's looking like definitely more accurate overall.

And the water test seems to show the TCR around 0.0014 - very nice.

 

[TheBloke]

Although, boo to springy!

 

[Landman]

Yeah, I was a little disappointed in that. I was expecting it have little to no spring at all.

 

[druckle]

Yeah, I was a little disappointed in that. I was expecting it have little to no spring at all.

Try torching the material to relax the work hardening and see if the spring doesn't disappear. If you're up to it repeat your tests to determine if properties (TCR etc.) change for the annealed material. Many stainless steels show pronounced physical propertiey changes depending on work hardening state. That would mean if we wanted to use the material for vaping we'd want to do it in the fully annealed state to avoid changes in service that would foul up the temp accuracy.

Duane