Miniature Smoke Alarm

[thenightowl]

For me a much more pleasing size and 2 for £4 a must buy! For sale in Morrisons. Comes with batteries.

 

Stay safe!

 

Peter

[ChrisPy]

I believe the current thinking is that the old type alarms should be replaced with the new generation optical alarms. They don't cost a lot, but are apparently less likely to give false alarms. No doubt Rob at BSS will confirm the current thinking.

[1066]

For me a much more pleasing size and 2 for £4 a must buy! For sale in Morrisons. Comes with batteries.

 

Stay safe!

 

Peter

 

I bought a couple from Asda .... the batteries in the first one lasted just over a fortnight before the unit started bleeping out a 'low battery' warning.

 

I haven't tried the second one yet ... perhaps I was just unlucky. They take CR2032 flat cells.

[thenightowl]

For me a much more pleasing size and 2 for £4 a must buy! For sale in Morrisons. Comes with batteries.

 

Stay safe!

 

Peter

 

Thank you for informatin Chris, BS 5446 appears to only refer to "Ionization Chamber".

 

Peter

[thenightowl]

I bought a couple from Asda .... the batteries in the first one lasted just over a fortnight before the unit started bleeping out a 'low battery' warning.

 

I haven't tried the second one yet ... perhaps I was just unlucky. They take CR2032 flat cells.

 

Will let you know if mine goes the same way?

 

Peter

[pwl]

I use alarms that use the CR2032 battery in the house. Search ebay and you can get 50 ot 100 replacements for a lot less in most stores.

 

P

[1066]

I use alarms that use the CR2032 battery in the house. Search ebay and you can get 50 ot 100 replacements for a lot less in most stores.

 

P

 

Just out of interest, how long do they last in your alarms?

 

The small smoke alarms each use three of these batteries .... which means that the batteries cost more than the alarm!

[blackrose]

Which should I go for, ionisation or optical smoke alarms? Or one of each perhaps?

 

I notice the ionisation type have a radioactive element inside them. Is there any cumulative radiation exposure risk if it's only a few feet away? It's probably no more than background levels, but the fact that they mark it with a radioactive symbol is enough to put one off. I mean if there are radioactive particles sitting there over your head it can't be good can it? Better than being roasted alive I suppose...

Edited April 27, 2008 by blackrose

[Ex- Member]

Which should I go for, ionisation or optical smoke alarms? Or one of each perhaps?

 

I notice the ionisation type have a radioactive element inside them. Is there any cumulative radiation exposure risk if it's only a few feet away? It's probably no more than background levels, but the fact that they mark it with a radioactive symbol is enough to put one off. I mean if there are radioactive particles sitting there over your head it can't be good can it? Better than being roasted alive I suppose...

 

I would have thought the levells were safe even to high exposure times and smaller areas. The battery issue puts me off more, having to replace too regularily leaves the opportunity to forget to replace batteries. Hopefully 1066 had a bad set of low batteries in it to begin with. Nice sized unit though, impressive

Edited April 27, 2008 by Julynian

[pwl]

Just out of interest, how long do they last in your alarms?

 

The small smoke alarms each use three of these batteries .... which means that the batteries cost more than the alarm!

 

About 3-4 months

 

P

[ChrisPy]

Which should I go for, ionisation or optical smoke alarms? Or one of each perhaps?

 

I notice the ionisation type have a radioactive element inside them. Is there any cumulative radiation exposure risk if it's only a few feet away? It's probably no more than background levels, but the fact that they mark it with a radioactive symbol is enough to put one off. I mean if there are radioactive particles sitting there over your head it can't be good can it? Better than being roasted alive I suppose...

good basic advice here. It seems that for most purposes on a canal boat the optical is the best bet, Mike. But nothing to stop you fitting both, they are both so cheap.

 

http://www.firekills.gov.uk/smoke_alarms/02.htm

[blackrose]

good basic advice here. It seems that for most purposes on a canal boat the optical is the best bet, Mike. But nothing to stop you fitting both, they are both so cheap.

 

http://www.firekills.gov.uk/smoke_alarms/02.htm

 

Thanks Chris.

 

Screwfix do mini battery powered photo-electric alarms. http://www.screwfix.com/prods/97772/Securi...ric-Smoke-Alarm

 

Is this the same as an optical alarm? They also have optical mains alarms so I wondered why they called one optical and the other photo-electric?

Edited April 28, 2008 by blackrose

[wonderdust]

yes they are the same

 

clicky

 

Generally, there are two kinds of smoke alarms – ionisation and photoelectric.

Ionisation Smoke Alarms

They ‘smell’ the smoke. This type detects invisible particles of combustion e.g. from cooking toast. They activate more quickly for fast, flaming fires and little visible smoke.

 

Advantages

 

Cheaper than other types

 

Very good with fast flaming fires with little visible smoke

Suitable for general use

Less prone to false alarms due to dust and steam

Disadvantages

 

Very susceptible to nuisance alarms due to cooking

May be slow to respond to slow smouldering fires

Contain radioactive material

 

Photoelectric Smoke Alarms (also known as optical)

These ‘see’ the smoke (optical). This type detects visible particles of combustion e.g. smouldering cigarette smoke. They respond to a wide range of fires, but they are particularly responsive to smouldering fires and the dense smoke given off by foam filled furnishings or overheated PVC wiring.

 

Advantages

 

Good for smouldering fire and dense smoke

Not as prone to cooking nuisance alarms

Contain no radioactive material

Suitable for general use

Disadvantages

 

Prone to nuisance alarms from dust and insects - must be kept clean

More expensive

Edited April 28, 2008 by wonderdust