Hello, My Name Is…

Every so often, something so bizarre pops up that I end up just taking a few minutes to absorb just how utterly bonkers it is before either bursting out laughing or face-planting my desk.

In this instance, I didn’t do either. First, a little history. Most of you know Clive Bates. Once a week, he runs a search on PubMed on everything THR related. It’s then bundled up in a nifty e-mail that he sends to a nicotine consumer group which I’m in.

Most of the entries have his comments, usually coupled with an excerpt from either the abstract of a paper or the conclusion. This one caught my eye out of the 32 results in Clive’s e-mail. (Clive’s comments in red)

So, some researchers have designed a vaping machine. I had to check it out. Perhaps they’ve learned something.

Ladies and Gentleman, let me introduce you to the U-SAV:

This is their starting premise:

For the most part, the fundamental design of an electronic cigarette is the same regardless of whether you have an Aspire Cleito or a ProTank. However, most devices now are variable wattage; mostly because it allows regulated devices to meet the wattage requirement without unduly draining the cells, unlike variable voltage. A cell can only provide a finite amount of juice before it simply can’t do its job anymore.

As with the “Juice Monster” paper, the researchers miss a crucial point. Passing voltage through a resistant material will always generate heat. That’s how light bulbs and e-cigarettes work. Most devices that have the supposed ability to moderate temperature, don’t actually sense the actual temperature of the coil. Instead, they take known variables (resistance) and the temperature coefficient (what resistance the wire is at certain temperatures) and program the device to back off on the power when it gets to a certain (user-set) level.

Maybe they have been listening.

Or maybe they haven’t. Look. Under no circumstances, outside of a simulation, can a cell, or even a set of cells, provide a constant voltage. It is simply not possible. To truly simulate how a 18650 cell operates, perhaps the authors should take a look at the (widely available) discharge charts for commonly used cells.

Seems fairly reasonable for once. Puff for 3 seconds (which is about average for most users), then rest for 27. Rinse and repeat. But hang on:

Unless you are a chain vaper – and I know one or two – this simply isn’t realistic. After a few puffs, the coil will start to produce dry puffs because it is getting too hot.

Guess what happens when a coil heats up? Its resistance changes. Naturally, that doesn’t apply as much to a material used for temperature limiting such as SS316 or Ni200.

Figure 4a & 4b

As you’ll notice in the above chart, the resistance of the coil (a 1 Ohm Cubis head, SS316) signifanctly changes throughout the course of a single puff. In comparison, the amount of power (in watts) remains relatively stable; due of course to the regulation of power. I would, of course, be hesitant to vape on a 1 Ohm SS316 coil at 16W for a couple of reasons:

1. A 1-ohm coil is usually used for mouth to lung vaping, and usually doesn’t require a large amount of power for the users satisfaction
2. Applying a higher power to a coil that doesn’t have sufficient air-flow will result (eventually) in a dry puff scenario

Yet, look at this:

Figure 5 a, b & c

When set to variable voltage (which as we know isn’t at all possible), there’s variation in the power delivered (natch). It is, however, consistent (when set at 3.87V) with the variable wattage test. Suggesting that their crazy idea may actually have some merit.

Well, no shit Sherlock! Energy cannot be destroyed, but it can be transformed. Step to the front of the class. This is where a number of e-cigarette studies fail so dramatically.  It is also something decidedly lacking from a standard smoking machine.

Put it this way, very few vapers use their device in the same way they smoked. When smoking, the actual puff isn’t that intense. So all the previous studies that used smoking machines wouldn’t even come close to using the devices the way they are intended to be used.

Well, congratulations. You’ve finally caught on to how vapers use their devices. It’s only taken you a decade.

For once, I actually agree with a conclusion. But there’s a problem, and it has nothing to do with the paper itself.

This statement of COI is enough for many anti-ecig folk to completely ignore the contents of the paper and instead cry “Big Tobacco shills!”.

I wonder how long it will be before this paper is decried as an industry plot?