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Reading ohms too low


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To make sure, you're talking about SP 23 that went up Thursday? 

If so, it shouldn't exactly change the initial reading. What it should do is make the initial reading a lot more stable (less variation from sample to sample, or if you run atomizer analyzer) and it should fix a lot of the stainless steel control wobble. It may help the firing output. 

It also significantly improves how the case thermal are computed but only if it gets new coefficients. For starters, try 500 seconds cooling, 400 seconds heating, 8 degrees static and 18 degrees per amp. That should keep the room temperature reading pretty accurate. 

What are you reading for a cold resistance, what material, and what should you be reading?

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Yes I am using sp23.

Im using ss316 and on all my other devices the coils read at 0.5 ohms but on the 75c its reading at 0.46 ohms. Not a massive difference maybe, but its enough to take any sort of accuracy out of temp control.

I usually vape somewhere between 200 and 220 degrees C but to get anywhere near the same experience on the 75C I have to run at 240 and upwards, which means Im just guessing at the temperature.

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Gotcha! 

Three questions: .460 vs .500? I know it doesn't seem like much of a difference, but like you say stainless is really sensitive. 

In atomizer analyzer, what are each reading for room temperature and raw resistance?

What mod resistance do you have set for both devices? 

Is it now stable to vape on (just cold) or does it still have the same instabilities? 

If it is reading stably, then we can now chase down the missing .04 ohms. 

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No, case analyzer works correctly (finally) in this version. There's a bit of discrepancy depending on whether your theme charges with the screen on or off, but that's a couple degrees at most.

 

However, the default case thermals for the board are definitely wrong in most devices. So changing them manually to approximately what I posted above is recommended if your room temperature is significantly off. We'll push a device-specific update when these changes (and any others that show up while testing this one) get pushed to all users. 

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Using my Therions

Therion 75 . Raw 0.499/5    Room temp 73.2F   .0028 mod resistance

Therion 133.  Raw 0.501/2    Room temp 75.36F    .006 mod resistance

Therion 75BF.  Raw 0.498/9   room temp 73.5F    .006 mod resistance

Therion 75C.   Raw 0.464/5   room temp 27.25C   .003 mod resistance

 

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Okay, so it is now reading stably, the room temperature is a little hot but not enough to cause the effect, it just seems significantly miscalibrated. More than I've seen yet. But the A/D sampling changes we put in could have affected the calibration (which if so would be the easier fix than finding the sampling issue we had)

If you manually adjust the resistance on the 75C to .500 ohms, does it vape the same as the other devices? Similar smoothness, similar power, similar device monitor graphs?

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Yes if I manually adjust the resistance it feels more like what I would expect it to be like. The device monitor graphs look good and the vape is smooth.

The problem with that is as soon as the coil cools a little I get the "new coil" message, which gets annoying after a while.

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15 ore fa, John ha scritto:

If it is reading stably, then we can now chase down the missing .04 ohms.

Hello

Exacly same delta here with Therion 75C , it reads minus 0.04 ohms on cold coil .

With last SP23 , after performing case analyzer , at first glance I have much better results (after manually playing with Case static Temp rise parameter , which was not calculated by analyzer). Thanks !

regards , Francesco

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Well, I'm pretty much confirming all of the above:

1) SP23 improved "precision" of cold ohm sampling. Note I used "precision" as what has improved is the stability (or repeatability) of the measure. If I take several samplings, I get much more consistent and similar values (barring the physiological slight increase due to the measurement slightly warming the coil) than before (where it was more jumping here and there across different back-to-back measurements)

2) SP23 doesn't seem to have improved "accuracy" of cold ohm sampling: I took the same atomizer (a TC-friendly one, with no springs, direct center-pin-to-post positive path) with a SS316L coil on the therion 75C, the vaporshark 200 and an EvolvReferenceMod 200 and you can see the output from AA here below.

Keep in mind real room temperature is ~86F, so the ERM is the most accurate as far as room temperature goes.

The headline is: the 75C still reads lower, _my_ therion seems to be ~ 0.024 below (instead of 0.04), but that's still enough to swing the temperature by ~60F with SS316L. Unfortunately at the moment I don't have my other 75C which is out for repair, so I couldn't put that to test as well.

Oh, as a final note, manually correctly the cold ohm value on the 75C, brings the temperature value I have to use back to its normal 390/400F range, instead of the "tuned-by-taste" 475F value I need after a "real" cold ohm sampling.

Here we go:

 

EDIT: I'm sorry but I can't seem to find a way to avoid the attached screenshot being duplicated... I see each of them only once in preview, but then when I save the message they get duplicated...

 

therion.jpeg.e9ffb1028950529d35695a39c19fea53.jpeg

vaporshark.jpeg.98fee6a9e96e58b51e04f35c88658116.jpeg

ERM.jpeg.a9095f46cce0920a50fa0f4208dbd8df.jpeg

 

therion.jpeg

vaporshark.jpeg

ERM.jpeg

Edited by ndb
Tried to remove duplicated screenshots: failed, giving up
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Just want to rule something out... If you go into Tools -> Serial Terminal, what does it say if you send the commands

I=GET OFFSET

V=GET OFFSET

? (You will need to have fired a coil at least once for these values to not show up as 0.000.) Also, how did you power-up your device from cold? From USB? Fire button not connected to USB? Most importantly, what happens to the current and voltage offsets above if you send the command

R=SAMPLE OFFSETS

? I get -0.101A and -0.033V the first time around, and -0.109A and -0.031V the second.

Thanks!

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Dear Mr.James

Below my test results on Therion DNA75C:

Device powered up by fire button

I=GET OFFSET [RESULT=0.097A    ]
V=GET OFFSET [RESULT=0.034V    ]

R=SAMPLE OFFSETS
I=GET OFFSET [RESULT=0.090A]
V=GET OFFSET [RESULT=0.030A]
R=SAMPLE OFFSETS
I=GET OFFSET [RESULT=0.098A]
V=GET OFFSET [RESULT=0.034V]
R=SAMPLE OFFSETS
I=GET OFFSET [RESULT=0.090A]
V=GET OFFSET [RESULT=0.030A]
R=SAMPLE OFFSETS
I=GET OFFSET [RESULT=0.098A]
V=GET OFFSET [RESULT=0.035V]

SS316 coil measured on other device = 0,64 ohm
On therion 75C=   0,5998 ohm
delta=0,042 ohm
room temp 27 degc \ same result on mod

BR , Francesco

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Hi @James

just tried this on the therion 75C I used in the comparison in my previous post and I get these

1) After a couple of puffs: I=-0.156A, V=-0.037V

2) After R=SAMPLE OFFSETS: I=-0.154A, V=-0.045V

1 hour ago, James said:

Also, how did you power-up your device from cold?

I just unlocked it with the unlock sequence, then connected to Escribe and issued the commands you suggested after firing (I fired while connected to USB, for that matter).

I also realized I did this with the cold ohm value manually corrected to 0.695 (as it was reported by Vaporshark DNA200) instead of the 0.676 that coil sampling would have produced.

I don't know if this makes any difference and/or impairs the results in any way. If you need me to do it again with a standard sampled value for cold ohms, just let me know and I'll let the coil rest for a while and repeat...

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After a couple of puffs

Conditions = room temp 23°C - SS304 0,37 Ohms manually set to 0,338 (27°C) and locked - temp set to 200°C - 35 Watts Punch - 20 Watts Power limit

Maybe it helps you to see the numbers with this settings (manually set ohms and locked)

 

 

Screenshot at Juli 24 09-23-27.png

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Am 22.7.2017 um 19:15 schrieb Frank65:

hello attached my results on Therion DNA75C

Sorry if this is a stupid question (I'm new on DNA stuff) but do have i to calculate the static delta temp manually ?

Regards

Francesco

Untitled.jpg

I also get case static temp rise 0 degrees here when running case-analyser with the latest early sp.

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6 hours ago, James said:

Here is a firmware to try, SP24. We'll be including it soon with EScribe Suite SP5. It fixes some issues with resistance sampling, which may help here.

DNA 75 Color v1_1_SP24.sw-service

 

Early feedback, after installing SP24 on the ERM 75C:

looks very promising!

The SS316L build I have on it was consistently reading ~0.84 (against ~0.86 on DNA200/75) with SP <= 23. On SP24 I'm getting repeatable 0.859 / 0.862 cold ohm values and an apparently smoother power regulation (looking at device monitor on the mod only, as I'm on the move so I can't currently use Escribe too much), which might as well just be a side effect of the higher res sampling, preventing too aggressive throttling maybe?

Once back at home I'll do some more extensive testing and report back if I find anything meaningful.

All in all seems quite a good step forward for now.

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Just loaded up sp24, room temp is pretty spot on, so is resistance, but I still have to set the temp over 500f on the 75c to get the same vape I get at 410-430 on either of my 250s or my 60. Tried 3 different tanks, jobs engine, govad, and a melo3 with triton 316 coil. Both rtas had are also 316 coils

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Don't know if it's a little bug and don't think it's affecting the correct run of the board.I didn't test the latest release but once I set the mod resistance, it's resulting saved with a +0.0001.

In my case, I set it as 0 and I used the signature tips tool to calculate it (0.003) with the atom analyzer. I put and saved to the mod that value and after the saving  EScribe is showing 0.0031 ohm.

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@67exec, make sure you resample Cold Ohms.

The correction is small enough it won't necessarily ask New Coil? on its own. With incorrect Cold Ohms from earlier Service Packs it will be slightly cold.

Also, do your other devices have a mod resistance set? We default the 75 Color to 0.004 Ohms.

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