nocturneYSK Your smoke detectors should be replaced every 7-10 years
GorkThis is only true for the Americium based smoke detectors. The newer photoelectric cell fire detectors don’t decay like Americium detectors, and as long as you replace the battery it’ll be good for however long it’s internal components (capacitors and whatnot) will last.
Technology Connections has a good video about this subject:
There are two types of smoke alarm. One of 'em ain't so good.
According to the one i just had to replace, combo carbon monoxide detectors need to be replaced. I don’t know how the carbon monoxide part works, but i wonder if it’s a reagent or something.
This is anecdotical but I moved into an apartment with a 30 year old ionizing smoke detector, and the failure was it was too sensitive, I assume because there were less electrons being emitted from the radioactive element, any faint smoke caused it to go off. Eventually it got into a state where it would always be in an alert state, and was beeping 100% of the time, which was when the landlord finally replaced it.
My assumption with the 10 year replacement recommendation for Americium based smoke detectors is to replace it before it becomes too sensitive and annoying, because they were worried some people would remove the battery and just live without an active smoke detector.
There’s no radiation drop after just 30 years from americium 241. It has a 450 year half life. After decades electric components start to fail and\or things get dirty. After 30 years of getting smoke in it, there was probably a layer of dust\smoke over where the radiation is at that were blocking some of the radiation all the time, that made it more sensitive.
Same issues will happen with photoelectric detectors. It’s recommended to replace both types after no longer than 10 years. I have no idea where the person you responded to got the information about them not needing replaced as often as ionization detectors. If anything, it’s actually the opposite.
The half life for americium 241 is like 450 years. The 10 year replacement has nothing to do with decay. It’s just a non specific safety in case any of the electronics or board etc start to fail. Photoelectric detectors have the same 10 year recommendation as a max.
It’s actually recommend by many organizations (like the NFPA) to replace photoelectric detectors more often than ionization detectors, if anything.
It’s tuned to a specific output and isn’t exactly field adjustable. Certainly it will continue to be radioactive long after you’re dead, but that doesn’t mean it will still be working properly.
I know exactly how they work. I’m a firefighter and a hazmat technician. Plus I work on and repair electronics as a hobby. Your smoke detector failing after 10 or 30 years has zero to do with radioactive decay. It’s from contamination (dust) and sensor degradation. Once the metal plates inside get enough buildup from dust (like smoke dust and regular dust) and contamination from humidity, the charge that’s supposed to be detected between those plates from the ionization stays lower all the time. That means less actual “smoke” is needed to drop it below the threshold. This happens MUCH faster than radioactive decay reducing what it will ionize.
wonderingwandererA motion to rename every element that’s named after a place. All in favor updoot, all opposed downdoot
Okay, let’s start with Helium (named after the sun)
That’s a celestial object, not a place. The sun is traveling at 230 km/s around the galaxy. It’s not a “place.”
The sun is a place. The moon is a place. Earth is a place. A specific location on the earth is also a place.
Anything you insert into a sentence describing the origin point of something traveling is a place.
Okay, then how about renaming every element that’s named after a nation-state?
This is plain WRONG and DANGEROUS.
The issue is NOT the Americum but the natural degration of the photoelectric cells and the accumulation of dirt within the test chamber.
Even before that time the risk for false alarms is increased substantially by degration before the chances for sucessful alarming decrease rapidly. Due to that they actually withstand aging actually worse than ionisation based devices.
Sientific sources?
here.
(Besides: Americum has a decay time of over 400 years,btw)
Your third source is about the 2020 follow-up study of the 2017 study in your first source. You’ve “only” (in scare quotes because that’s still plenty) got three independent sources even though it looks like four.
Carighan MaconarAnd if you live for rent, at least over here in Germany your landlords are obliged to replace them regularly, but like you say that just means they’ll replace them with previous ones that have been checked and had batteries replaced.
Alec in his own video mentions that the issue isn’t that the Americium decays, but that the electronics themselves age and fail, which applies to both the ionization detectors and photoelectric detectors.
This is one of the things you just don’t wanna mess with, and from what I know some manufacturers are even beginning to make detector units with non-replaceable batteries, intended to be replaced whole when the battery dies after years of runtime, to make it impossible to keep using a detector after its rated lifetime.
I know some manufacturers are even beginning to make detector units with non-replaceable batteries, intended to be replaced whole when the battery dies after years of runtime, to make it impossible to keep using a detector after its rated lifetime.
I’m sure that’s the reason say they do it, but that smells like standard corporate planned obsolescence and profit seeking with a great PR excuse.
Yes, but no. You really should replace your detectors every decade. They will likely work perfectly for twice that, but is it worth the risk over like $100 in smoke detectors?
So it does sort of force you to replace it after a decade, but you should anyhow.
It’s also well worth it, because getting on a chair or ladder and buying new overpriced 9v batteries every year (if you’re all proper about changing them) is a pain in the ass compared to once a decade. The more of a pain it is to get to your detectors, the more a 10 year one becomes worth it.
You’re supposed to hit your test button once a month to check their functions, but I dont think anyone anywhere actually does that. If they tell me they do I’ll just assume they’re a liar.
BluetreefrogIt’s more to do with improved battery technology. New detectors have lithium batteries that last the same ten years as the detector.
I am an engineer and it’s just legitimately hard to build any kind of sensor that lasts and stays accurate longer than like 10 years especially without maintenance. They do intentionally design them so that they don’t last longer, but that’s because a design that would last longer would costs like 10x as much and require a lot of maintenance and calibration that your average homeowner is simply not going to do. It’s honestly surprising you can make an accurate smoke detector that even lasts 10 years as cheap as they are.