New studies find carcinogens in vg and pg at high temps, even in tootle puffers
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I was just sent this bit of interesting Info. I just skimmed it but found it interesting all the same, and thought those of you that are able to digest it more fully would also. I am not a researcher, but I did sleep at Days Inn last night.
This dated 19 Jan. 2018;
Farsalinos Exposes Faults in Formaldehyde Vape Studies - Vaping360
This dated 11 Jan. 2018;
Carbonyl Emissions in E-cigarette Aerosol: A Systematic Review and Methodological Considerations
Seems that the fine folks at New England Journal of Medicine are at it again with flawed research.
This dated 19 Jan. 2018;
Farsalinos Exposes Faults in Formaldehyde Vape Studies - Vaping360
This dated 11 Jan. 2018;
Carbonyl Emissions in E-cigarette Aerosol: A Systematic Review and Methodological Considerations
Seems that the fine folks at New England Journal of Medicine are at it again with flawed research.
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When I saw he was doing TC with Kanthal that was my assumption as well....then he posted this:
Now, I am not sure if you are questioning what Hohmtech is or if you are questioning the "it isn't really temp based at all" part.
If you don't know what Hohmtech is, and you are doing TC with Kanthal, then you are doing something very wrong. The Hohmtech mod is the ONLY mod on the planet (right now) that can you can even attempt TC using Kanthal with. You should not be using Kanthal in TC mode with any other mod.
If you are questioning the temp part, then allow me to explain. Most mods do TC by constantly measuring the resistance of the coil. Since TC compatible wires change resistance when heated in a predictable way the mod can calculate the temperature of the coil based on the resistance changes. The Hohmtech mod doesn't do that. It sends a digital signal through the wire and reads how fast/slow that signal is sent, as the coil heats and cools the signal speed changes and that is how it determines the temp of the coil. This is why it can work with Kanthal. Really neither method is truly measuring the temp, they are just calculating it in different ways. I have heard that the signal method is a bit more finicky especially as the ambient temperature (air temp around you) changes from it's original baseline measurement. For that reason I prefer the resistance measuring method.
From what I've understood the Hohmtech doesn't really measure temperature at all (the Evolv-type tc does, in the same way traditional mercury etc thermometers do). It's difficult to know for sure as Hohmtech had a tendency to provide plenty of fancy nonsense explanations. Clearly it works, however it does what it does, but the temperature values seem to be more or less arbitrary, set according to taste. Clearly, 93 degrees Celsius would give no vapor at all so that temperature value is seriously off.
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The Evolv DNA boards and every TC device currently in existence (other than Hohmtech) uses the resistance measuring method I mentioned above. That is why you can only use specific wires. There is no way for a mod to accurately measure temp of a coil the way a thermometer does. It would have to read the temp from the coil, through the build deck, through the bottom of the tank, and through the 510 connector. That is way too much metal in between.
The way they determine the temp is scientifically sound though. Many digital temp sensing devices use something called a thermistor to measure temperature. A thermistor is a resistor that changes resistance in reaction to temp changes. The digital circuit measures this resistance change of the thermistor to determine temp. Sound familiar? In normal TC devices, the coil itself acts as a thermistor in the circuit. This isn't really reading the temp though. It is just a way to measure something else and calculate the temp. The only way to measure temp directly without some calculation is with a liquid based thermometer (such as mercury or alcohol based thermometers) that directly reacts to the pressure changes caused by the temp changes OR a spring thermometer where a coiled spring expands or contracts moving a needle on a dial.
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My understanding of science is limited (I went the humanities and social sciences route), but seems that I have understood the hows and whys of Evolv tc fairly well, though my ability to explain it is lacking. I guess what I mean, in the comparison of Evolv tc and what Hohmtech does, is that the former uses clear and set parameters to approximate its temperature calculations whereas the latter uses a set of parameters that need to be set by the user and don't relate to temperature in a clear-cut and simple way. I'd love to have a good explanation, free of the Hohmtech buzzword-filled bs, how Hohmtech's kanthal tc actually works and how it relates to temperature. I'm not criticizing the device, but I'm annoyed by Hohmtech marketing speech.
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Yes, I am questioning the statement from Ken on the temp part of it, but, after I posted what I did, I thought better of it as I knew that if I got involved in a back and forth on the HohmTech technology then it would seriously clog up this thread and send it off the rails, which I didn't want to do. I realize that there are Fan Boys of Evolv that think Evolv is the be all and end all of Temp control, I don't happen to share those opinions. I still feel that Temp Control should be called Temp guessing at this early stage of the TC technology, no matter who is implementing it and how they do it. If I am inside my house and am enjoying 70°F temperatures, then go outside where (this time of year) it might be -25°F, I do have to adjust my G2 to get it back working like before, but even that is just a mild inconvenience, as it takes little effort to do. I do agree that trying to TC/TL Kanthal is a finicky operation, at best, but, I do it every day and see no more problem in doing it with a HohmTech device than I would if I had a DNA or YiHi device, just 2 different ways to skin a cat, that's all. To say that the way HohmTech implements what they do is not Temperature Based, is not correct, but if it is being said that it might not be accurate then I won't argue at all, as I contend that NO TC is accurate, just guesstimation. I do think that all Temp devices can be made accurate (at least more so than what we have now), but we would pay thru the nose for such high tech circuitry. Do I think I am truly running at 93°C ?? NO !! That's why I run mine at the bottom of the scale all the time, but it is doing some sort of temp control, as when my wick dries out, my vapor peters out to nothing, and my wicks don't burn, only slightly singe, just like the DNA's and YiHi's do. So whatever HohmTech is doing, it's working for me.
I just did what I didn't want to do. Sorry folks, that is to those of you still awake and haven't been put to sleep.
P.S. When I set a SS build at 93°C and the same watts as Kanthal in my G2, I got pretty close to the same vapor out of each, which wasn't much, but that's how I vape. Either similar to what a cigarette gets me, or a little less, and always a Cool vape, not even warm. If that helps Scott. I'm a bit different in my vape likes, that's why I was asking about the bigger wire and more vapor questions earlier a few pages back, as I have always vaped like this and don't know what it is like or how to get there from here without burning up my wicks in Power mode.
Ahh, I understand what you getting at. I did try to explain the way HT does it as simply as possible. I do agree about their marketing though.
What turned me OFF from Evolv was watching post after post of folks complaining about their DNA 40's and getting no response from Evolv in helping them out, or replacing defective units. That's why I never bought into the whole TC thing until HohmTech came along and TC/TL'd Kanthal. I was waiting for Evolv to do the same thing, but they never did. I, still to this day, have a hard time typing "Temperature Control", if you notice I will type "TC/TL" instead, but am still not happy with that description, I just still feel too uneasy with it being called that, but that's all we got to work with at this point. Now HohmTech is out of the Mod business, they went to Battery Technology instead, and left all us with no Warranties at all now on what we have bought. But, I'm still glad I have what I have from them.
I think I understand their Technology Scott, and have for quite a while. One does have to read between the lines to understand it though, at least I did, and being as I'm an Old Fart, it took a while to soak in. I think of it as using "Ping" Technology, like what computers do when they "Ping" remote sites to see if someone is home, and they measure that time to get a reference number for the base resistance reading. Am I close ??
I think I understand their Technology Scott, and have for quite a while. One does have to read between the lines to understand it though, at least I did, and being as I'm an Old Fart, it took a while to soak in. I think of it as using "Ping" Technology, like what computers do when they "Ping" remote sites to see if someone is home, and they measure that time to get a reference number for the base resistance reading. Am I close ??
I have to disagree, especially on the price bit. You can buy a digital clock on Amazon for a mere $8.99 that detects room temp using the EXACT SAME TECHNOLOGY. They use a thermistor, measure resistance and calculate the temp....pretty accurately too I might add. Now the clock does have an advantage in that it uses a known thermistor and can be calibrated for that one component and it only has to check every minute or so. Where as a mod has to be able to handle any coil a user throws at it and it has to calculate multiple times per second. So that does add some complexity, but cost should be only slightly higher. I think the reasons so many mods fail to do TC accurately, is more in the base values (such as internal resistance), the frequency and accuracy of the resistance measurement, and the software itself. I also think that lot of the cheaper ones are just throwing something together as fast and cheaply as possible, put TC accuracy as a second thought and have low QC standards. Some mod makers have taken the time to make TC quite accurate though. Evolv, Modefined, and a couple of others have put more focus on TC and are more accurate. The clock makers know they need to get the temp right and have been around for years to get it right. As TC becomes more mainstream I expect more mods will put more effort into accuracy. I do not expect it to impact pricing much at all.
I have always thought that the impurities in the wire have something to do with it, and the circuitry is not accurate enough to detect and compensate for it automatically. Like some of the Chinese devices are said to be calibrated to, say, 316L SS, but folks have to screw around with the TCR value and put it on something that is technically OFF by alot just to get the device to work, and even then it keeps jumping out of TC all the time, or at least enough to be bothersome. I was thinking that if they used more expensive components then this crappy wire could be compensated for and adjusted in circuit and brought back into spec so the device would work as advertised. I was thinking that it was just due to price point, but...
I didn't word that quite right, I hope you got my meaning though. I guess that I was trying to give them a Pass on the accuracy part, it made sense to me, but guess I was wrong on that.
You got any Snow down there ?? My brother got some over in Austin and said that everyone was in the ditch, that they still don't know how to drive in Snow or on Ice. That was a couple weeks ago BTW.
You got any Snow down there ?? My brother got some over in Austin and said that everyone was in the ditch, that they still don't know how to drive in Snow or on Ice. That was a couple weeks ago BTW.
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I have seen a lot of hand soldering done on these mods, so internal resistance is prolly all over the place.
I disagree, and I have the data to prove that a properly built and calibrated DNA is accurate within ~10 degrees, measured with a NIST certified thermocouple and meter and sound techniques. I also wrote a blog on the topic of how to achieve the best accuracy.
The ping technology provides a "relative" temp control, but it is only relative to a baseline that the user provides, and that "baseline" is not based on physics but rather on the users judgment. Yes, a ping echo is based on physics and time, but it does not correlate directly to temperature, only to the relative difference in temperature against the user selected baseline.
Where tcr based control, when implmented properly, is actually able to measure temperatures in degrees as it pure math and physics.
No, it is not as accurate as my NIST traceable test equipment, but it is as accurate as Evolv claims. It is not "guessing".
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Agreed, that is why you should measure the internal resistance of the mod and plug that into the software as an offset. Escribe provides methods to do this.
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This is kinda what I've been trying to so, unsuccessfully [emoji5]
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To what Quantitative Value would you consider TC to be "accurate" ?
+/- 10F ?
+/- 5F ?
+/- 1F ?
+/- .01F ?
Something else perhaps?
I was just sent this bit of interesting Info. I just skimmed it but found it interesting all the same, and thought those of you that are able to digest it more fully would also. I am not a researcher, but I did sleep at Days Inn last night.
This dated 19 Jan. 2018;
Farsalinos Exposes Faults in Formaldehyde Vape Studies - Vaping360
This dated 11 Jan. 2018;
Carbonyl Emissions in E-cigarette Aerosol: A Systematic Review and Methodological Considerations
Seems that the fine folks at New England Journal of Medicine are at it again with flawed research.
As always nice to see stuff from Dr. F. The NEJM letter (not a peer reviewed article) is the same one from 2015, not anything new. At least based on the link Dr. F provided in his link.
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