High Initial Resistance Readings...

[sig-cmt]

Pop on cold atty which reads 0.14 across multiple ohm meters. DNA 200 invariably reads this as 0.16. Fifteen minutes later, the reading drops to 0.15 and it is only after a few hours of sleep and refinement when the correct reading of 0.14 is reached. Is this normal? 510 threads and pins on both the device and atty are confirmed clean (visually and by way of cleanings with DeOxit D-Series). What are some best practices for obtaining accurate cold resistance readings in the shortest amount of time?

[DannyK9]

sig-cmt said:

Pop on cold atty which reads 0.14 across multiple ohm meters. DNA 200 invariably reads this as 0.16. Fifteen minutes later, the reading drops to 0.15 and it is only after a few hours of sleep and refinement when the correct reading of 0.14 is reached. Is this normal? 510 threads and pins on both the device and atty are confirmed clean (visually and by way of cleanings with DeOxit D-Series). What are some best practices for obtaining accurate cold resistance readings in the shortest amount of time?

Sounds like a daft reply but do you know for certain the other ohm readers are accurate ? You could lock the ohms when it reaches 0.14 In general most ohm meters and devices I've dabbled with are almost always out by 0.1 .2 its no big deal

[black lace]

are you checking resistance from the bottom of the atty , with the mulit tester, this is where the mod will be doing it at the 510 connector on mod, is point of contact, if your putting two ends of a multi tester across each lead of a coil I don't think 0.02 is much of a loss.
hope that ain't as clear as mud

[topline580rp]

I Have noticed similar, on DNA 40 and 200 the resistance always reads higher than on any other devices i own, Currently a Uwell Crown that reads 0.142 and 0.145 on sx350 and ipv d2 respectively, Reads 0.159/0.160 on DNA 200, I was wondering why this would be all else being equal, Any knowledgeable replies would be gratefully received.

[Jaquith]

The simple answer is Accuracy and Calibration with the added variable of Conductivity. Most Meters are cheap with cheap (female) 510's their accuracy that's reliable to the 1/10th Ohm some are fractionally better. Next is Calibration, most Multimeters have a calibration setting to zero-out the resistance of the wires and then the accuracy might be 1/100th. The variable that's the hardest to control is the Conductivity which is one of the reasons Evolv employs a Dynamic Lock as opposed to a hard Atty lock. None of this suggests a 'Reading' can't register a 1/100th (0.01) on a cheap Ohm Reader nor 1/1000th (0.001) of an Ohm on a Mod. TC control looks at a relative change over time. Terms like 'jump or drift or jitter' Resistance inaccuracies adversely effect accurate TC. Most DNA 200 Mods are not properly set up and I've seen Resistance Calibrations off by as much as 0.020 Ohm. Materials, the Atty's 510 can be very unstable and some Atty's simply are so bad in TC their use isn't recommended, including plating. Next are the materials used female on your Mod and the pressure applied to the 510 and the conductivity of the materials plus the length of wires, solder points, calibration, etc. The 'etc' can be effected quite a bit by Oxidation, Plating, Contact and Debris. I strongly recommend maintaining your 510's and cleaning with a solvent eg Isopropyl alcohol both your Atty's and especially you Mods. Most TC Mods are have an accuracy 10 fold over your cheap Resistance Meter.

[topline580rp]

Hi Jaquith, I get what you mean about all the variables that can alter a resistance reading, I was wondering why a dna40 flask and a reuleaux dna 200 which are different chips and different mods but only share the fact that they are both evolve chips would both read the same coil at 0.160 and two mods that are sx based but different mods and chips would read at about 0.145 using the same coil that was used on the dna,s,
Is there something in evolves software dna40 and dna200 that increases that value ?

[Jalcide]

Use the Atomizer Analyzer and twist the atty to see if it fluctuates. You may be able to find a sweet spot and observe the lower value you're seeing on other mods.

Also, in addition to cleaning contacts with a solvent, a small, micro fiberglass "scratch pen" can work wonders on copper and brass contacts. Just be sure to wash out the tiny fiberglass remains anywhere there is juice or air intakes.

The scratch pen has brought several attys back to life, for TC.

As to why the DNA readings you're getting are consistently higher, and not lower, just make sure your observations are more than would be expected from a coin toss.

[Jaquith]

topline580rp said:

Hi Jaquith, I get what you mean about all the variables that can alter a resistance reading, I was wondering why a dna40 flask and a reuleaux dna 200 which are different chips and different mods but only share the fact that they are both evolve chips would both read the same coil at 0.160 and two mods that are sx based but different mods and chips would read at about 0.145 using the same coil that was used on the dna,s,
Is there something in evolves software dna40 and dna200 that increases that value ?

My 'guess' is calibration offsets and by no means am I thinking it's irrelevant. The DNA 40 had no calibration options, that I'm aware of anyway nor does an SX350J (non M Class; yep they're different) which some Modder's used. So if there were any calibration offsets they came from YiHi and were internal to their resellers on an OEM basis. Evolv went more the open source route. YiHi might of guessed a 'global' offset ie an average?!

However, the current DNA 200 with Firmware does offer a 'Mod Resistance' offset to the user. Temperature Control works as a prediction to 'change' and the math works as a fraction (percentage) change.

So lets test the math:

DNA 0.16 + (120%) = 0.192 - 0.16 = 0.032
YiHi 0.145 + (120%) = 0.174 - 0.145 =0.029

0.032 (not equal) 0.029 ; 10% difference; so a 10% change of 0.030 Ohm's on some TCR's might mean 5F on others 50F. True might be in the middle .. who knows.

That's why this setting is hugely important of the DNA 200:
 

LOL if you think your DNA is correct with 0, it's not. Frankly, I took an old Atty and silver soldered the positive and negative then with the 'Mod Resistance' at 0 run the Atomizer Analyzer .. whatever value it reads gets plugged into the Mod Resistance. On every Mod it's going to be slightly different .. which is exactly why I run my own including on my Reuleaux, Vapor Shark, etc.

[Jalcide]

I just discovered something. I think the DNA 200 shows something other (higher) than cold ohms.

Other mods may be showing true cold ohms.

For example, right now I have a genesis atomizer running nickel with a displayed reading of 0.12 ohms on the mod, itself.

If I run the Atomizer Analyzer it shows cold ohms at 0.116.

So, it knows the build is lower, but is choosing to show a higher number.

The Nominal Ohms read at .129. Raw ohms (being heated slightly by the readings) shows 1.37.

My guess is that the DNA chip is compensating and giving a more real-world "cold" reading that is somewhere between the real cold reading and a resting nominal reading (or something similar).

Or maybe it's just rounding it up because of the constraints of the display's decimals (*blush*). That's probably it. Never mind. I'm an idiot.

[VapingBad]

It does, it uses the room temp derived from board temp + case thermals and refinement mode (tracking the resistance as the coil and the mode cool during idle).  It is a evolution of what the DNA40 does with room temp an refinement mode, they do their best to get an accurate cold resistance regardless of the box they are fitted in.  This is why Evolv have only said the mod and coils should be at the same temp when fitted and not at room temp like less sophisticated boards.

[Jalcide]

VapingBad said:

It does, it uses the room temp derived from board temp + case thermals and refinement mode (tracking the resistance as the coil and the mode cool during idle).  It is a evolution of what the DNA40 does with room temp an refinement mode, they do their best to get an accurate cold resistance regardless of the box they are fitted in.  This is why Evolv have only said the mod and coils should be at the same temp when fitted and not at room temp like less sophisticated boards.

I suspect all that subtlety happens within that 3rd, 1000th decimal place?

If so, in my example, if my cold reading were 0.114, and thus maybe rounded down on less sophisticated boards, maybe the DNA's refinement pushes it just enough to get a "round up" for the display.

*shrug*

[VapingBad]

MY guess is a physical connection issue Jalcide with the mod construction, there is only so much the board can do.  This week an Origenny V2 I have been vaping for about a week went up from 0.09 to 0.15 ohm and I checked and re-checked everything, after at least a day of this I gave the negative screw a tighten with an proper L shaped Allan key/hex wrench and bang back to 0.09 ohm.  But I had tightened this screw with a FT Allen key screw driver as soon as the problem occured to the extent it rounded off the hex corners before and would have been very tight by most peoples standards.  It was using Ni200 ribbon wire sleeper coils so maybe the ribbon need to be crushed more, but it was stable at 0.09 for about a week before.

[Jaquith]

Jalcide said:

...For example, right now I have a genesis atomizer running nickel with a displayed reading of 0.12 ohms on the mod, itself.

If I run the Atomizer Analyzer it shows cold ohms at 0.116.

So, it knows the build is lower, but is choosing to show a higher number.

The Nominal Ohms read at .129. Raw ohms (being heated slightly by the readings) shows 1.37.

My guess is that the DNA chip is compensating and giving a more real-world "cold" reading that is somewhere between the real cold reading and a resting nominal reading (or something similar)...

Unless your Atty while running the Analyzer is jumping all over the place while moving the Atty on the Mod, don't 'Lock Resistance' and instead let it adjust automatically. Between vaping sessions the DNA compares the Cold Resistance auto locks the new resistance. IF you are a TC aficionado then run all of the Analyzers the DNA 200 offers, and do that Mod Resistance as I described. Example my Reuleaux is not the vanilla 0.003 Ohms. However, I'm confident its ability to measure resistance is accurate enough once calibrated. Tips: the gunk on your coils is an insulator and will progressively throw off the temperature. Keep your coils clean. The metal shavings/juice, black grit, on your 510's also throws off a temperature by changing the resistance; clean. The constant temperature changes of your coil loosens the wire and creates resistance jumping; tighten your coils.

[Jalcide]

Thanks, guys. Yup, doing all that. But no issues here, I was just providing a hypothetical case to explain why maybe the refinement could, in certain edge cases, round the resistance shown on the mod up to the nearest 10th, compared to a mod without refinement.

My EFusion DNA 200 + Rocket R CloudDeck genny + 200 SS mesh with Ni200 is the best vape I've ever had. The TC works so well, I can have the wattage set to 200 and not worry about a single dry hit; flavor is dialed in by degrees F, alone.

Even looking at the graph, it's almost a perfectly flat line when it reaches the desired temp. Pretty amazing.

[topline580rp]

Hi Guys, Thankyou all for your input, As i said in my last post this difference has been noticed on dna 40 and 200 All using a number of nickel uwell coils,I have swapped and swapped across the 2 x SX based mods and DNA40/200 mods and it works out to be a solid 0.01 and approaching 0.02, I have very clean 510s using 99% isopropyl alchohol and done my box thermals which came to the same values that i have seen from wismec on a post on this forum,  This difference in resistance has me running my dna,s at about 470f and my SX,s at about 410f all things being equal.
I am not one of the Johns of this world or like a lot of you guys on this forum who are very clever around electronic facts and possibilities ( No disrespect intended ) I am just a user who flying by the seat of my pants knows that there is something different between the DNA,s and the other two very different/similar mods that i have mentioned,
I really like what john has done with this product and the interaction we can have with it but i wont be alone in noticing this difference, it might be that the dna is the product that is giving me the true vape experience but all i know is and the bottom line is SX mods for me and my set up and vape style = 410f and DNA mods = 470f.
For me as a relatively uneducated person in terms of electronics i just need to know why the difference is there because I KNOW IT IS, so i can move forward knowing that the resistance values i see with SX350/ipv d2 is just plain wrong or that the DNA values are different because of ?? 60f is quite a difference when all of us are just trying to get Vaporisation at a safe and consistent temperature (clouds and flavour are secondary) And really is the WHOLE point of the DNA 200. Thanks in advance