Mission Statement - De-Spinning the Pro-Taser Propaganda

Yeah right, 'Excited Delirium' my ass...

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The primary purpose of this blog is to provide an outlet for my observations and analysis about tasers, taser "associated" deaths, and the behaviour exhibited by the management, employees and minions of Taser International. In general, everything is linked back to external sources, often via previous posts on the same topic, so that readers can fact-check to their heart's content. This blog was started in late-2007 when Canadians were enraged by the taser death of Robert Dziekanski and four others in a short three month period. The cocky attitude exhibited by the Taser International spokespuppet, and his preposterous proposal that Mr. Dziekanski coincidentally died of "excited delirium" at the time of his taser-death, led me to choose the blog name I did and provides my motivation. I have zero financial ties to this issue.

Saturday, August 21, 2010

Setting standards for tasers in Canada - screwing up the details?

Montreal Gazette [via TNT] [LINK]
OTTAWA — A team of researchers led by a Carleton University professor has developed a new system for consistently testing the thousands of Tasers used by Canadian police. Andy Adler, a Canada Research Chair in biomedical engineering, working with five other academic and industry experts has established a method for agencies across the country to test Tasers and other "conducted-energy weapons" and determine whether the devices are operating within their manufacturers' specifications. ...

Adler said the testing procedure the authors are recommending goes beyond the guidelines proposed by manufacturer Taser International. "Taser has their guidelines, but they needed to be augmented," Adler said. "We made a much, much more specific protocol." ...

A maximum-charge limit is also being proposed based on electrical safety specifications. Currently, Taser calls for an average charge of 125 microcoulombs, a measurement derived by combining the intensity of a charge and the time it lasts. The new protocol calls for a maximum charge of 182 microcoulombs. ...

Thunk, thunk, thunk [the sound of my head repeatedly banging the table]

I can only hope that this is simply incomplete reporting, and not engineering insanity.

Let me explain...

The 125 microcoulombs reportedly quoted by Taser International is the electrical charge emitted by (for example) the X26 taser...


Let me first point this out - way back in March 2009, I explicitly pointed out [see my post Masters of Understatement] that their written specification at the time of "100uC" (100 microcoulombs) seemed to be a bit low.
"This simple analysis indicates that 100uC might be just a bit of an understatement."
It really appears (and this is the first I recall of seeing "125 microcoulombs") that they either read my post (oh yes they do!), or perhaps they finally figured it out for themselves, that "100uC" was a bit of an understatement. So they changed the spec to match the uncontrolled, randomly-chosen, accidentally-higher-than-stated, actual output?

What did I fricken' tell you?

How is your confidence level in the skills of the Taser International engineering staff holding up? Does it actually require a unknown blogger [me] with a straightedge and a crayon [LINK] to correct their work?

Geesus H...



Back to the main point...  The 125uC charge in the pulse repeats with each pulse. And the X26 pulses repeat at either 17 or 19 pulses per second (various spec sheets quote these two values). Multiply 125uC by 17 pulses per second and you get the deceptive "2.1mA average" so often mentioned by Taser International.

Specifying the maximum charge per pulse is not a complete safety specification. Not when the number of pulses isn't mentioned (I'm only reading the news). If the pulses repeated at 10,000 pulses per second, then the subject would probably start smoldering. You have to pay attention to the time axis. Not just per pulse.

Especially that it's perfectly obvious that Taser International will feel free to adjust the specs ("100uC") to match the product as built ("125uC") without so much as blink. Or change the pulse rate from 19 to 17 pulse per second, or perhaps 28 next time. Or completely change their "magic" (sic) waveform from the M26, to the X26, to the XREP, to the X3 - all without any oversight whatsoever.


As I wrote above, I can only hope and pray that this obvious omission is simply incomplete reporting and not an engineering oversight.


ALSO: Given that even 125 uC repeated at 17 or 19 pulses per second is already established as potentially lethal by (among other) the Braidwood Inquiry and the evidence from the real world, what the heck has gone wrong that the ultimate limit has been set almost 50% higher still?

With the bell curves already overlapping and deaths resulting, allowing another 50% is not a good idea. Due to the shape of the bell curves, things get worse more quickly than you might expect.

Thunk, thunk, thunk [the sound of my head repeatedly banging the table]

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