You can get much better deals than that. Plus this is the one that lasted much less than the brand in the living room, so I'll be looking for that one now.
-- Regards, Joerg http://www.analogconsultants.com/
Oh, that's nasty, a built-in expirtion counter. I sure won't buy that brand again.
-- Regards, Joerg http://www.analogconsultants.com/
Yeah, plus it's not worth the time considering that one can by a good brand for $30-40.
It still passes self-test. Normally they must make sure that it won't go dead without notification, at least not for residential use. Because that can result in nasty lawsuits.
Self-testing should be rather easy by measuring the quiescent current of the fuel cell.
-- Regards, Joerg http://www.analogconsultants.com/
It passes self-test. Once it doesn't it would sound a chirp and blink. It is from a very reputable company (Kidde) and I am sure they won't risk major lawsuits via sloppy design.
No. I was just wondering why this one quit so much earlier than another brand.
I won't wait for a sale, has to be replaced. Cuz I don't want to get killed dead, as John Wayne would have said.
-- Regards, Joerg http://www.analogconsultants.com/
Let's play with the numbers: Q: What are your chances of dying for CO poisoning? A: CO-related deaths account for an approximately 0.2% of the approximate 2 millions deaths per year in the US. Of those CO deaths, suicides account for 47.8%, fires 21.9%, motor vehicle exhaust 9.5%, domestic fuels 2.8%, homicides 1.5%, and pipeline gas 1.1%.
Out of a population of 320 million, we therefore lose 4,000 people each year to CO poisoning, half of which were intentional (suicide) leaving 2,000 deaths in the home that might be preventable with an alarm. The odds of accidentally dying in the home per year from carbon monoxide poisoning is: 2000 / 320 million = 6.3 parts per million = 0.00063% = 1 chance in 160,000 According to the National Safety Council: those odds are about the same odds as getting hit by lightning. Perhaps the government should mandate portable lightning arrestors?
Extra credit for dividing the annual CO alarm sales by 2,000 preventable deaths to determine the cost of prevention per life saved. I couldn't find any sales figures.
-- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558
As someone else mentioned - that one might simply not be complaining about having expired.
Read the label before parting with money!
I would - how else would I know when its no longer safe to rely on?!
Den fredag den 9. maj 2014 19.00.42 UTC+2 skrev Ian Field:
yeh I'd say it is a nice feature that is basically forces you to get a new one when it is most likely no longer reliable
-Lasse
By measuring the fuel cell current and noticing when it shows a gradual drop-off.
-- Regards, Joerg http://www.analogconsultants.com/
CO poisoning also sends tens of thousands to the hospital per year, lights flashing and sirens wailing. AFAIK one of the longterm consequences after surviving a heavy dose of CO is Parkinson's.
How many people were saved by CO detectors warning them?
-- Regards, Joerg http://www.analogconsultants.com/
Brilliant! So, if you buy it and store it for 5 years, then plug it in, it blindly goes on for 5 years after the cell has died, telling you that it is protecting you when it is no longer sensitive to CO. Not a great plan!
Jon
do your light bulbs go bad when you store then in a drawer? shelf life and power life is not the same thing.
-Lasse
I harvest components from my old CFLs, the high voltage transistors aren't as useful as I'd hoped, but most contain a diac which are getting scarce via the usual routes of supply.
Finite lifespan for the sensor. Replaced ours the third (or 4th?) time recently. Bought a 10-year (fixed) life lithium battery powered unit, since it was clear that its cost over 10 years was going to be a lot less than feeding the one $5 cheaper 3 AA batteries on a regular basis...
Our really old (first) one did not have an end-of-sensor-life routine, so it would happily sit there and pretend it was fine. It wasn't. The next one mentioned sensor lifetime prominently on the package, and died messily when its time came (chirping and gibbereish on the display, rather than a nice EoL or Err). The new one comes with a sticker you can fill out to remind yourself that yes, it has been that long, when it starts complaining in another 9 years and a bit.
You may not like just replacing them on a time basis, but it's a fairly standard approach to life-safety items - the sensor is probably good for
12-15 years, depending on how paranoid the lawyers are, but the EoL is going to be 10 years from the date it's turned on (this one does not turn off, at least until you push the "disable for recycling" irrevocable switch that it has; probably right before you crack it open and start recycling "non user serviceable parts")-- Cats, coffee, chocolate...vices to live by Please don't feed the trolls. Killfile and ignore them so they will go away.
Statistics are wonderful for sizing a power plant or phone infrastructure. But, when it comes right down to it, YOU're the only one that counts when it's dead or alive. I'm sure those 2000 dead people will be comforted by your statistics.
As for me, I'm gonna go push the test button on all my CO detectors.
So, how are you gonna tell when to replace it? Might as well just cut the wire to the chirper and keep the one you have. Of all the things to obsess over...
Where my life is at stake I prefer to test them with a small scale known source of CO and establish that it really does trigger. My wife is not enamoured of this practice since the dose/time rules tend to result in banishing the thing to the garage until it calms down.
In theory yes, but in practice it is down to how well they designed it. A fail dangerous device might not be able to even sound the alarm and be merrily "bleeping" to tell you that it has a fault condition.
Mine has a health LED to say "yes I am still working". I don't trust it!
Unfortunately people do design fail dangerous devices. The most amusing we produced was one that involved a 9000K plasma playing on an actively cooled pinhole cone sampler to vacuum at 8kV and behind that hard vacuum. The entire system was designed to protect the expensive pumps.
Very little thought had been given to the waste water sump (most were to be fair run on a recirculating chiller). One installed in a basement developed a fault on the exit side leading to bulk water escaping and the header tank cistern could more or less keep up with demand...
As a software engineer I only trust hardware interlocks if the kit has the potential to fry me to a cinder, crush or otherwise kill me. YMMV
-- Regards, Martin Brown
Imagine if the same logic was applied to something like the TSA, or the whole war on terror
-Lasse
I was hoping that it would measure the actual sensor fuel cell current and use that information to find end-of-life, not just a dumb timer.
-- Regards, Joerg http://www.analogconsultants.com/
Normally they have a silence button. What do you use as a CO source?
Oops ...
Same here. AFAIK the CO detectors do use hardware. It shouldn't be too hard to use the fuel cell current to trip a comparator and to then trigger a beep alarm when the current has dropped too low. Ideally it should even issue a warning a few weeks before it gets to that level, to give folks enough time to buy a new detector.
-- Regards, Joerg http://www.analogconsultants.com/
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