The importance of accuracy in a TC mod

[ScottP]

So a lot of people are always asking which mod they should get, and I ALWAYS tell them to watch DJLSB or PBusadro Youtube reviews to make sure what they are buying is accurate. Especially if they are looking for a TC mod.

Well I am looking for a new TC mod for the wife and started watching mod reviews, just to see what is available. The very first one I watched (Pbusardo review of the Vaporesso Switcher) and I saw this (see image below). Note the first 2 sets of bars are for Ni200 and it doesn't do too bad a job there, the next sets are for Titanium and SS316L respectively. WOW, just WOW.

For Titanium setting this to 400F, you will actually be vaping at 863F!!!!! This thing is up to 460F HIGHER than what it is set to. It's not much better for SS316L, firing 563F while set to 400F and 819F while set to 500F. Considering juice starts breaking down into various aldehydes above 450F, this thing will put you WAY into the danger zone without you even knowing you are vaping that high, based on your settings.

This is why it is so important to make sure the device you are using is at least reasonably accurate and why I can easily recommend DNA boards from Evolv. So if you are planning to vape TC, please watch a review by one of these 2 guys to make sure it does what it says.

 

[Rossum]

For Titanium setting this to 400F, you will actually be vaping at 863F!!!!!

Not if your wick and coil are kept properly wet. In that case, it's pretty hard to get more than 50-100F above the boiling point of the liquid, but that can still be a ways into aldehyde generating territory, and of course this is clearly cotton or rayon scorching territory if things dry out.

IMO, the dry cotton scorch test is still an excellent and practically free way to tell if a TC mod is in the ballpark with any particular coil.

 

[ScottP]

Not if your wick and coil are kept properly wet. In that case, it's pretty hard to get more than 50-100F above the boiling point of the liquid, but that can still be a ways into aldehyde generating territory, and of course this is clearly cotton or rayon scorching territory if things dry out.

IMO, the dry cotton scorch test is still an excellent and practically free way to tell if a TC mod is in the ballpark with any particular coil.

While technically true, my point is when you think you are vaping safely at say 435F, this thing is really going to be pushing probably close to max power through your coil and juice.

 

[Fredman1]

Shocking and interesting. First time I see a chart like that. That should be THE go to chart for any TC mod really....Makes me wonder about my TC mods now...
You know how the temps are measured to record on the chart?

 

[ScottP]

Shocking and interesting. First time I see a chart like that. That should be THE go to chart for any TC mod really....Makes me wonder about my TC mods now...
You know how the temps are measured to record on the chart?

Yes a thermocouple is placed on a dry coil then fired. A properly working TC Circuit should keep the coil temp within a close range to the setting.

For instance, here is the same chart showing a comparison between the DNA 60 (red), DNA 75 (green) and DNA 75C (purple). The blue bar is what temp the device is set to. Notice how close they all are with the 75C being the most accurate but slightly lower than setting. Using this device you would pretty much know you are in the safe zone. Accuracy is what makes these boards worth the money, the warranty doesn't hurt either.

 

[Alien Traveler]

Amateurs (read Busardo) at their best. OK.

 

[Fidola13]

While technically true, my point is when you think you are vaping safely at say 435F, this thing is really going to be pushing probably close to max power through your coil and juice.

Well that’s somewhat upsetting because that’s THE main reason I’ve been using TC albeit I vape closer to 400F but that’s a lot of leeway.

 

[Coastal Cowboy]

A few points:

1. You're right--accuracy is important in TC vaping because without accuracy you might as well be in power mode.
2. "TC" is just a software model of what's supposed to be a real world phenomenon. There is no "thermostat" in the device measuring temperature. Temperature is a calculated value based on a known relationship with resistance.*
3. Placing a thermocouple inside the device has a chance of affecting the data being collected because the thermocouple has mass and will absorb some energy itself.
4. If it's reading a dry coil then it's not measuring a real world phenomenon. No one fires a dry coil in real life. Without evidence to the contrary, we have to assume that whoever wrote the code that does the TC would not worry about the temperature of a dry coil.
5. The temperature of a dry coil will run away if power is not regulated. This is like a car being under a driver's control at 50mph and being uncontrollable at 100mph.

I don't own a Vaporesso Switcher.

*A lot of people don't know this.

 

[ScottP]

1. Placing a thermocouple inside the device has a chance of affecting the data being collected because the thermocouple has mass and will absorb some energy itself.
2. If it's reading a dry coil then it's not measuring a real world phenomenon. No one fires a dry coil in real life. Without evidence to the contrary, we have to assume that whoever wrote the code that does the TC would not worry about the temperature of a dry coil.
3. The temperature of a dry coil will run away if power is not regulated. This is like a car being under a driver's control at 50mph and being uncontrollable at 100mph.

Note: the numbering auto changed when I removed the first 2 points, which I agree with.

1. Yes the thermocouple can absorb some energy, meaning the mod may have to expend more to maintain the desired temp. However, if the mod is calculating the temp of the wire correctly, then it should NOT affect the measured temp. Even if it did, the reading would be slightly lower, not nearly DOUBLE the set temp.

2. Again, wet or dry the resistance of the coil will still change at the same rate based on the actual temp of the wire. Calculating temp based on wire resistance is actually OLD technology and used for many things beyond vaping. Most of those other uses are actually dry scenarios. Now, the max temp a coil should be able to reach will be lower in a wet setting vs dry, but wet or dry should not affect the mods ability to calculate the temp based on the wire resistance.

3. Yes a dry coil temp only has power as a regulating factor, while a wet one has evaporation as another limiting factor. I think you are missing the point though. This mod in question is obviously NOT regulating power correctly or the coil would never have gotten that hot. If the mod was accurately measuring resistance and calculating temp correctly it should be shutting power down LONG before reaching 800+F. To use your car analogy, this is more like setting your cruise control to 60mph and the car actually flooring the accelerator and going as fast as the car possibly can. That would be a flawed design and completely unsafe to use, as is this mod IMHO.

 

[Fredman1]

I agree...wet or dry, the resistance stays the same. In the end its all about the quality of the board..

 

[ScottP]

I will add that I am not sure if the flaw is in the actual hardware, or in the software that does the calculations. If it is just a software problem they may fix it in a later firmware update. However, unless someone retests it after the update, we won't know if it is actually accurate or just less flawed.

 

[Coastal Cowboy]

Note: the numbering auto changed when I removed the first 2 points, which I agree with.

1. Yes the thermocouple can absorb some energy, meaning the mod may have to expend more to maintain the desired temp. However, if the mod is calculating the temp of the wire correctly, then it should NOT affect the measured temp. Even if it did, the reading would be slightly lower, not nearly DOUBLE the set temp.

This is not true, because everything having mass inside the chamber will affect not only temperature, but the rate of change in temperature. That includes the wicks and the liquid.

2. Again, wet or dry the resistance of the coil will still change at the same rate based on the actual temp of the wire. ... Now, the max temp a coil should be able to reach will be lower in a wet setting vs dry, but wet or dry should not affect the mods ability to calculate the temp based on the wire resistance.

Yes, but the actual temperature of the wire is also regulated by the liquid being vaporized. The point I'm trying to make is that Busardo collected some interesting data but that the data isn't useful because it doesn't represent what would actually be happening with a TC-moderated atomizer that's vaporizing juice. It's interesting but not useful in a real world setting.

I agree...wet or dry, the resistance stays the same. In the end its all about the quality of the board..

The quality of the chip doesn't control how it's been programmed. "TC" is not a chip on a board. It's a program in a chip on the board. The chip can only do what it's told to do, and by measuring a dry coil, Busardo hasn't told us whether the Vaporesso programmer told the chip to do the right thing.

 

[ScottP]

This is not true, because everything having mass inside the chamber will affect not only temperature, but the rate of change in temperature. That includes the wicks and the liquid.

Yes wick, juice and airflow will affect the temp, but NOT the resistance of the coil at a given temp. If they did then calculating temp based on resistance change would NOT work at all. Thus if the device measures a specific resistance change, then regardless of the other factors then the coil should be reasonably close to the calculated temp no matter of how fast or slow it got there or what mass it has. This is why TC can work on both a single strand wire with low mass and huge exotics with large mass. The resistance change is based solely on actual temp of the wire. If you cool the coil with liquid or by blowing on it, or whatever, the resistance to temp ratio is CONSTANT.

Yes, but the actual temperature of the wire is also regulated by the liquid being vaporized. The point I'm trying to make is that Busardo collected some interesting data but that the data isn't useful because it doesn't represent what would actually be happening with a TC-moderated atomizer that's vaporizing juice. It's interesting but not useful in a real world setting.

Again the resistance to temp relationship is CONSTANT so wet, dry, air flow, mass, all affect temp but NOT how it's calculated. See my point above for details.

The quality of the chip doesn't control how it's been programmed. "TC" is not a chip on a board. It's a program in a chip on the board. The chip can only do what it's told to do, and by measuring a dry coil, Busardo hasn't told us whether the Vaporesso programmer told the chip to do the right thing.

The "chip" is simply a computer that runs a program to calculate data and send out signals according to the software. However there is more to the circuit than just the "chip" that helps it collect data on the resistance of the coil, among other things. So it could either be a hardware issue or a software issue. Most likely it will turn out to be some miscalculation in the software, but that is not a guarantee.

EDIT: If you think this device is safe to vape in TC, be my guest, but don't say you weren't warned.

 

[ScottP]

I'll add one more case point to demonstrate what I mean. As mentioned before this is old technology, one common use is in modern digital clocks that measure and display the room temp. They also use a metal wire and measure it's resistance change to determine the temp. If you stick this clock in a freezer then obviously the cold air on the wire will affect the wires temp but will NOT affect the clocks ability to read the resistance change and properly calculate the temp. If you move the clock to an oven preheated to 120F the hot air from the oven will also affect the temp of the wire, but again will not affect the clocks ability to read the resistance change and calculate the temp.

Just like the clock, the wick, juice, and airflow WILL affect the temp of the coil but NOT the mods ability to read the resistance of the coil and calculate the temp of said coil. The problem with this mod in particular is that it is NOT calculating the temp properly and regulating power accordingly.

 

[Coastal Cowboy]

Yes wick, juice and airflow will affect the temp, but NOT the resistance of the coil at a given temp. If they did then calculating temp based on resistance change would NOT work at all. Thus if the device measures a specific resistance change, then regardless of the other factors then the coil should be reasonably close to the calculated temp no matter of how fast or slow it got there or what mass it has. This is why TC can work on both a single strand wire with low mass and huge exotics with large mass. The resistance change is based solely on actual temp of the wire. If you cool the coil with liquid or by blowing on it, or whatever, the resistance to temp ratio is CONSTANT.

Yes, and the variable in the equation is temperature. Resistance is the dependent variable. Temp is the independent variable. No changes in resistance cause changes in temperature. Any change in temperature changes resistance. Since temperature is independent, any method of measuring it that (a) can itself change the data and (b) doesn't measure how the object will be used can't be relied upon to assess the reliability of the model.

Again the resistance to temp relationship is CONSTANT so wet, dry, air flow, mass, all affect temp but NOT how it's calculated. See my point above for details.

And since it's temperature that drives resistance, AND since we agree that Busardo's method of measuring temperature is problematic, the conclusion that the TC model on the chip being examined is faulty is not valid.

The "chip" is simply a computer that runs a program to calculate data and send out signals according to the software. However there is more to the circuit than just the "chip" that helps it collect data on the resistance of the coil, among other things. So it could either be a hardware issue or a software issue. Most likely it will turn out to be some miscalculation in the software, but that is not a guarantee.

No dispute that the DNA chip is better than the Vaporesso. I dispute whether the chart above demonstrates that.

EDIT: If you think this device is safe to vape in TC, be my guest, but don't say you weren't warned.

I don't own one nor do I plan to. I use Smoant and Eleaf devices. The latter use the JoyeTech chipset, which are Arctic Fox compatible. I can't measure actual temp in real time, but I can monitor calculated temp in real time and taste the vapor while I'm doing it. It tastes like it works.

I don't know if Busardo has measured the JoyeTech chipset or not. But I wouldn't trust those data any more than I would the data on the Vaporesso if he did it the same way.

And look... Busardo isn't exactly a TC sharp. He thinks (or thought) THAT the preheat function was part of TC.

 

[englishmick]

So a lot of people are always asking which mod they should get, and I ALWAYS tell them to watch DJLSB or PBusadro Youtube reviews to make sure what they are buying is accurate. Especially if they are looking for a TC mod.

Well I am looking for a new TC mod for the wife and started watching mod reviews, just to see what is available. The very first one I watched (Pbusardo review of the Vaporesso Switcher) and I saw this (see image below). Note the first 2 sets of bars are for Ni200 and it doesn't do too bad a job there, the next sets are for Titanium and SS316L respectively. WOW, just WOW.

For Titanium setting this to 400F, you will actually be vaping at 863F!!!!! This thing is up to 460F HIGHER than what it is set to. It's not much better for SS316L, firing 563F while set to 400F and 819F while set to 500F. Considering juice starts breaking down into various aldehydes above 450F, this thing will put you WAY into the danger zone without you even knowing you are vaping that high, based on your settings.

This is why it is so important to make sure the device you are using is at least reasonably accurate and why I can easily recommend DNA boards from Evolv. So if you are planning to vape TC, please watch a review by one of these 2 guys to make sure it does what it says.

View attachment 723505

Interesting. I started trying out TC a couple of weeks back on a Jac, which has a DNA75 board.

I have some Picos and I was getting ready to give them a shot. I found a review by DJSLB which includes those same charts. It showed the Pico being quite accurate for SS which is what I used. The recorded temp was a little higher than the mod setting, but not much. The temp I liked best on the Jac was 380 so the difference DJ found on the Pico still leaves me well below the suspect level.

Thanks for posting this.

 

[englishmick]

Yes, and the variable in the equation is temperature. Resistance is the dependent variable. Temp is the independent variable. No changes in resistance cause changes in temperature. Any change in temperature changes resistance. Since temperature is independent, any method of measuring it that (a) can itself change the data and (b) doesn't measure how the object will be used can't be relied upon to assess the reliability of the model.

And since it's temperature that drives resistance, AND since we agree that Busardo's method of measuring temperature is problematic, the conclusion that the TC model on the chip being examined is faulty is not valid.

I don't have enough scientific understanding to assess whether the critique in your first para is valid. Actually thinking about it make my head hurt. I have a feeling that it might be one those things where it makes the results not absolutely trustworthy, but not valueless either.

I think @mikepetro did some of his real life temp measurements to assess the accuracy of his mod's TC settings. If so that might give some support (or not) to the dry temp reading numbers. It's late. Maybe I'll try to find that tomorrow.

 

[ScottP]

And since it's temperature that drives resistance, AND since we agree that Busardo's method of measuring temperature is problematic, the conclusion that the TC model on the chip being examined is faulty is not valid.

I am not going to rehash the rest but this is probably the most problematic of your statements. Let's say the method of measure was to blame, then why is this the ONLY mod he has ever tested that was off by 400+F? Using the same method and the same equipment to measure multiple devices would have shown every device to be this far off, if that were the case. Furthermore, even this device did reasonably well with Ni200 wire, just not with Ti and SS. So again if the flaw was in his method, that would NOT be the case.

Sure the method may not be 100% accurate and may in fact be off by a few degrees higher or lower, but considering many other mods he has measured (including but not limited to the DNA devices), including this mod with Ni200, do in fact show to be working in expected ranges, you cannot fault the test method for this large of a discrepancy. So I can ABSOLUTELY say with 100% confidence this mod is faulty in it's current state for use with Ti and SS wires. Again they may (or may not) fix this with a firmware update at some point.

Also if you watched the actual video, when he was actually trying to vape TC prior to measuring, he complained that it seemed to be significantly hotter than what he set it for and that was with wick and juice in your real world scenario. The testing just showed why it seemed that way....it actually was hotter than it was set for.

 

[ScottP]

I don't know if Busardo has measured the JoyeTech chipset or not. But I wouldn't trust those data any more than I would the data on the Vaporesso if he did it the same way.

Actually I found this review of the JoyeTech eVic Primo Mini (not sure if they all use the same hardware and firmware or not), but this one did reasonably well. Spot on for Ni200, slightly high for Ti and slightly low for SS. If his methods were as bad as you say then why is this also not off by 400F? I would have no problems recommending this device for TC especially if used with SS or Ni200.

 

[Coastal Cowboy]

I am not going to rehash the rest but this is probably the most problematic of your statements. Let's say the method of measure was to blame, then why is this the ONLY mod he has ever tested that was off by 400+F? Using the same method and the same equipment to measure multiple devices would have shown every device to be this far off, if that were the case. Furthermore, even this device did reasonably well with Ni200 wire, just not with Ti and SS. So again if the flaw was in his method, that would NOT be the case.

Sure the method may not be 100% accurate and may in fact be off by a few degrees higher or lower, but considering many other mods he has measured (including but not limited to the DNA devices), including this mod with Ni200, do in fact show to be working in expected ranges, you cannot fault the test method for this large of a discrepancy. So I can ABSOLUTELY say with 100% confidence this mod is faulty in it's current state for use with Ti and SS wires. Again they may (or may not) fix this with a firmware update at some point.

Also if you watched the actual video, when he was actually trying to vape TC prior to measuring, he complained that it seemed to be significantly hotter than what he set it for and that was with wick and juice in your real world scenario. The testing just showed why it seemed that way....it actually was hotter than it was set for.

I think we're losing our audience.

All I'm saying is that Busardo's testing indicates a problem but that since his test method is faulty, the data aren't good enough to reach the conclusion that it's not safe. The biggest problem I have isn't how the data were collected. It's that the dry coil data don't describe how it will be used by the average vaper. It's a problematic device that needs more scrutiny.

Remember the tests that anti-vaping Stan whatshisface did trying to prove vaping was harmful? He tested e-cigs in a way no vaper would ever actually do twice. He caught hell.

Thanks for posting the chart on the Evic. Joyetech, Eleaf, Wismec and a couple of others use the same chipset and all are Arctic Fox capable. I still don't trust the results--same faulty approach of using a dry coil.