Author Topic: Kr-85  (Read 13152 times)
wattMaster
Member
*****
Offline

Gender: Male
View Posts
View Gallery


WWW
Re: Kr-85 « Reply #60 on: September 08, 2016, 08:17:08 PM » Author: wattMaster
What If "eco" people reject starters because they think "There's radioactive stuff in those, I don't want any of it."?
Logged

SLS! (Stop LED Streetlights!)

Medved
Member
*****
Offline

Gender: Male
View Posts
View Gallery

Re: Kr-85 « Reply #61 on: September 09, 2016, 02:16:00 AM » Author: Medved
What If "eco" people reject starters because they think "There's radioactive stuff in those, I don't want any of it."?

Then say them they have to annihilate themselves, because they are radioactive too...
Logged

No more selfballasted c***

Ash
Member
*****
Offline

View Posts
View Gallery


Re: Kr-85 « Reply #62 on: September 09, 2016, 08:16:07 AM » Author: Ash
Speaking of which, how about smoke detectors ? There is some noise about their radioactivity (of the radioactive types), but is it really the reason for the more common use of the optic types now ? As far as i understand, each is more sensitive to smoke from different materials
Logged
Medved
Member
*****
Offline

Gender: Male
View Posts
View Gallery

Re: Kr-85 « Reply #63 on: September 09, 2016, 02:20:16 PM » Author: Medved
Speaking of which, how about smoke detectors ? There is some noise about their radioactivity (of the radioactive types), but is it really the reason for the more common use of the optic types now ? As far as i understand, each is more sensitive to smoke from different materials

The optical system is more sensitive (when adjusted still without false alarms) to the early, smouldering stage of the fire.
The ionization detectors react only to the products of hot burning flames, so with the most common house fires respond way later.
The difference published in literature is around 15 minutes, which is a lot.
This is the main reason, why fire codes are discouraging from the usage of the ionization systems and really encourage to switch to the optical systems.
Of course, when the disaster starts from a hot, rather clean burning flame, the ionization would be faster, but that type of fires is way less common.

So I would guess the reason for ionization detectors loosing grounds is not that much their radioactivity, but just their performance...
Logged

No more selfballasted c***

Ash
Member
*****
Offline

View Posts
View Gallery


Re: Kr-85 « Reply #64 on: September 09, 2016, 03:44:27 PM » Author: Ash
Dont the type of burning material have bigger effect ? Smoldering Wood vs Plastics ?
Logged
wattMaster
Member
*****
Offline

Gender: Male
View Posts
View Gallery


WWW
Re: Kr-85 « Reply #65 on: September 09, 2016, 05:13:02 PM » Author: wattMaster
Then say them they have to annihilate themselves, because they are radioactive too...
Oh, but then they'll say "But that's natural radiation, I don't want any of this artificial stuff.".
Logged

SLS! (Stop LED Streetlights!)

Medved
Member
*****
Offline

Gender: Male
View Posts
View Gallery

Re: Kr-85 « Reply #66 on: September 10, 2016, 02:21:46 AM » Author: Medved
Dont the type of burning material have bigger effect ? Smoldering Wood vs Plastics ?

It more depends on how the fire starts. If it is set by a torch or similar already clean burning flame, it will start as a clean burning fire.

But if the ignition source is something overheating, today most frequently some part of an electrical installation or so, it could be smoldering for half a hour or so before the first flame really pops up.

And the statistics show, most victims goes on the smoke account, already present in the smouldering phase (the "victim" here includes those who loose consciousness, so are not able to flee in time). Many "just" smouldering fires have a lot of victims even when these had never burst up into the open flame stage (because the fire just run out of the oxygen in that room and then slowed down or even died by itself)...
Logged

No more selfballasted c***

Ash
Member
*****
Offline

View Posts
View Gallery


Re: Kr-85 « Reply #67 on: September 10, 2016, 04:09:10 AM » Author: Ash
The standard for flame retardant Plastics used for electrical connection boxes etc is extinguishing after 10 seconds in open flame

Then, assume we have a connection box, somewhere in it a hot connection. The connection is hot but its smoke is escaping into the void of the wall (throught the holes around cable going into an open knockout etc) and possibly even sucked there by air flows entering around the box cover, so none of it reaching the smoke detector in the room at all

When the connection burst into flame, the flame starts melting the box and set it on fire. As the connection can burn for unlimited time (if the wires in the box are bent so, the melted isolation does not cause them to short), the box may continue burning according to the standard because the source of flame is still applied

(in addition, many of the connection boxes on the market are marked as flame retardant but fail the 10 sec test. The problem is the boxes, but we do need the smoke detector to react in this case too)

In general, the problem i see is that the directions in which the smoke distributes can change when it is changing from smoldering to open flame, because open flame tend to set other things on fire easier. So it may happen, that only in the flame stage the smoke starts to reach the smoke detectors



The proper solution would be to install smoke detectors in the wall voids or so too (in houses built like in the USA, where the wall inside is big void with only the wood frames in there). But i never seen that being even a recommendation for home users. Only in offices or so they install detectors above the drop ceiling or under the floor (for removable floor with cables going below) in addition to ones in the room itself
Logged
FGS
Member
*****
Offline

Gender: Male
View Posts
View Gallery

Rory Mercury!


Re: Kr-85 « Reply #68 on: September 10, 2016, 08:45:16 AM » Author: FGS
The residential walls doesn't have one big void in the walls. They have multiple voids. So a typical house would need a lot of smoke detectors to fill the wall voids.

A solution would be to mount the detectors in the voids that has boxes in them. The ones where there's nothing or cable runs thru the void are simply ignored. (Same rule applies for ceiling/floor voids.)

Or the houses can use steel studs which have cut outs on them for cabling and plumbing instead of wood which you have to drill holes on them to run anything thru them. (Advised to run metal armored cables instead of plastic sheathed cables. Those holes are razor sharp!)
Logged

Why I like LEDs on top of other lighting tech?
LEDs = Upgrade 95% of the applications. (That is if you avoid eBay's LEDs).


LED brainwash? No, people uses them cuz they work well for them.

Ash
Member
*****
Offline

View Posts
View Gallery


Re: Kr-85 « Reply #69 on: September 10, 2016, 09:25:41 AM » Author: Ash
When the voids are isolated from each other the risk of fire spread from one to another is low, it can as easily spread outside through the wall

Here drywall interior walls are installed on thin sheet Metal beams, but ocasionally a wall is made so there is some bigger void behind it, that may span more than one room or floor. And sometimes there are cables and connection boxes and other stuff installed in such void. Here it is less of a fire risk because the beams are Metal and the wall itself is fire retardant Plaster, but i can imagine a void like that on Wood framed structure could be a place for fire to hide for a while
Logged
wattMaster
Member
*****
Offline

Gender: Male
View Posts
View Gallery


WWW
Re: Kr-85 « Reply #70 on: September 10, 2016, 09:51:01 AM » Author: wattMaster
What are you even talking about? Burning wood? ???
Edit: Now I get it. Smoke alarms!
But is there a smoke alarm that uses Kr-85?
« Last Edit: September 23, 2016, 05:16:07 PM by wattMaster » Logged

SLS! (Stop LED Streetlights!)

Print 
© 2005-2024 Lighting-Gallery.net | SMF 2.0.19 | SMF © 2021, Simple Machines | Terms and Policies