are optical smoke alarms better for less false alarms than ionising
ones...in practice I mean ? .....

On Mon, 17 Sep 2018 21:12:48 +0100, "Jim GM4DHJ ..."
wrote:

are optical smoke alarms better for less false alarms than ionising
ones...in practice I mean ? .....

No. Neither have significant false alarm rates. Both however can
suffer nuisance alarms, these are not false alarms but real alarms
produced by non- dangerous activities such as steam from a bathroom
or overheated toast.

Optical suffer more from steam, ionisation from the combustion
products of things like singed toast. Used and sited properly neither
should have a significant nuisance alarm rate (unless of course you
are prone to overheating toast with the toaster is in the bathroom
sink while you are taking a shower).

On 17/09/2018 23:12, Peter Parry wrote:
On Mon, 17 Sep 2018 21:12:48 +0100, "Jim GM4DHJ ..."
wrote:

are optical smoke alarms better for less false alarms than ionising
ones...in practice I mean ? .....

No. Neither have significant false alarm rates. Both however can
suffer nuisance alarms, these are not false alarms but real alarms
produced by non- dangerous activities such as steam from a bathroom
or overheated toast.

Optical suffer more from steam, ionisation from the combustion
products of things like singed toast. Used and sited properly neither
should have a significant nuisance alarm rate (unless of course you
are prone to overheating toast with the toaster is in the bathroom
sink while you are taking a shower).


There are different types, at least 3, of detectors which are
recommended for different rooms/areas for just the reasons you say.
Placing the right one in the right location/checking it has been done is
the kind of thing I'd expect a competent Building Inspector to be able
to do. May be a call to the local council?

--

Smile for the camera ;-)
https://www.youtube.com/watch?v=HxyL2_38EsQ
Remarkable Coincidences:
The Stock Market Crashes of 1929 and 2008 happened on the same
date in October. In Oct 1907, a run on the Knickerbocker Trust
Company led to the Great Depression.

On Mon, 17 Sep 2018 23:21:58 +0200, Brian Reay wrote:

On 17/09/2018 23:12, Peter Parry wrote:
On Mon, 17 Sep 2018 21:12:48 +0100, "Jim GM4DHJ ..."
wrote:

are optical smoke alarms better for less false alarms than ionising
ones...in practice I mean ? .....

No. Neither have significant false alarm rates. Both however can
suffer nuisance alarms, these are not false alarms but real alarms
produced by non- dangerous activities such as steam from a bathroom or
overheated toast.

Optical suffer more from steam, ionisation from the combustion products
of things like singed toast. Used and sited properly neither should
have a significant nuisance alarm rate (unless of course you are prone
to overheating toast with the toaster is in the bathroom sink while you
are taking a shower).


There are different types, at least 3, of detectors which are
recommended for different rooms/areas for just the reasons you say.
Placing the right one in the right location/checking it has been done is
the kind of thing I'd expect a competent Building Inspector to be able
to do. May be a call to the local council?

This may help:

https://tinyurl.com/ybkdbm2s

--
My posts are my copyright and if @diy_forums or Home Owners' Hub
wish to copy them they can pay me £1 a message.
Use the BIG mirror service in the UK: http://www.mirrorservice.org
*lightning surge protection* - a w_tom conductor

On Mon, 17 Sep 2018 23:21:58 +0200, Brian Reay wrote:

On 17/09/2018 23:12, Peter Parry wrote:
On Mon, 17 Sep 2018 21:12:48 +0100, "Jim GM4DHJ ..."
wrote:

are optical smoke alarms better for less false alarms than ionising
ones...in practice I mean ? .....

No. Neither have significant false alarm rates. Both however can
suffer nuisance alarms, these are not false alarms but real alarms
produced by non- dangerous activities such as steam from a bathroom
or overheated toast.

Optical suffer more from steam, ionisation from the combustion
products of things like singed toast. Used and sited properly neither
should have a significant nuisance alarm rate (unless of course you
are prone to overheating toast with the toaster is in the bathroom
sink while you are taking a shower).


There are different types, at least 3, of detectors which are
recommended for different rooms/areas for just the reasons you say.
Placing the right one in the right location/checking it has been done is
the kind of thing I'd expect a competent Building Inspector to be able
to do. May be a call to the local council?

I went for a compromise:
https://www.toolstation.com/shop/p52932
FireAngel ST-622:
https://www.safelincs.co.uk/fireange...k-smoke-alarm/
--
Peter.
The gods will stay away
whilst religions hold sway

"Brian Reay" wrote in message
news
On 17/09/2018 23:12, Peter Parry wrote:
On Mon, 17 Sep 2018 21:12:48 +0100, "Jim GM4DHJ ..."
wrote:

are optical smoke alarms better for less false alarms than ionising
ones...in practice I mean ? .....

No. Neither have significant false alarm rates. Both however can
suffer nuisance alarms, these are not false alarms but real alarms
produced by non- dangerous activities such as steam from a bathroom
or overheated toast.

Optical suffer more from steam, ionisation from the combustion
products of things like singed toast. Used and sited properly neither
should have a significant nuisance alarm rate (unless of course you
are prone to overheating toast with the toaster is in the bathroom
sink while you are taking a shower).


There are different types, at least 3, of detectors which are recommended
for different rooms/areas for just the reasons you say. Placing the right
one in the right location/checking it has been done is the kind of thing
I'd expect a competent Building Inspector to be able to do. May be a call
to the local council?

optical detectors were uncommon in the battery powered domestic situation
when I retired in 2010 .....I mainly dealt with things like shopping centres
and an airport.....I left chicken feed to my staff....tee hee

On 17/09/2018 21:21, Brian Reay wrote:

There are different types, at least 3, of detectors which are
recommended for different rooms/areas for just the reasons you say.
Placing the right one in the right location/checking it has been done is
the kind of thing I'd expect a competent Building Inspector to be able
to do. May be a call to the local council?

Your local FPO would be a better source of advice.

--
Spike

"Spike" wrote in message
...
On 17/09/2018 21:21, Brian Reay wrote:

There are different types, at least 3, of detectors which are
recommended for different rooms/areas for just the reasons you say.
Placing the right one in the right location/checking it has been done is
the kind of thing I'd expect a competent Building Inspector to be able
to do. May be a call to the local council?

Your local FPO would be a better source of advice.

yes they are more active fire precautions ......

On Mon, 17 Sep 2018 23:21:58 +0200, Brian Reay wrote:


There are different types, at least 3, of detectors which are
recommended for different rooms/areas for just the reasons you say.
Placing the right one in the right location/checking it has been done is
the kind of thing I'd expect a competent Building Inspector to be able
to do. May be a call to the local council?

All a building inspector will do is point you Volume 1 of Part B of
the Building Regulations

https://www.gov.uk/government/public...ved-document-b

which says :-

Positioning of smoke and heat alarms

1.10 Detailed guidance on the design and installation of fire
detection and alarm systems in dwellinghouses is given in BS
5839-6:2004. However, the following guidance is appropriate
to most common situations.

1.11 Smoke alarms should normally be positioned in the circulation
spaces between sleeping spaces and places where fires are most
likely to start (e.g. kitchens and living rooms) to pick up smoke in
the early stages of a fire.

1.12 There should be at least one smoke alarm on every storey of a
dwellinghouse.

1.13 Where the kitchen area is not separated from the stairway or
circulation space by a door, there should be a compatible interlinked
heat detector or heat alarm in the kitchen, in addition to whatever
smoke alarms are needed in the circulation space(s).

1.14 Where more than one alarm is installed they should be linked so
that the detection of smoke or heat by one unit operates the alarm
signal in all of them. The manufacturers’ instructions about the
maximum number of units that can be linked should be observed.

1.15 Smoke alarms/detectors should be sited so that:
a. there is a smoke alarm in the circulation space within 7.5m of the
door to every habitable room;
b.they are ceiling-mounted and at least 300mm from walls and light
fittings (unless, in the case of light fittings, there is test
evidence to prove that the proximity of the light fitting
will not adversely affect the efficiency of the detector). Units
designed for wall-mounting may also be used provided that the units
are above the level of doorways opening into the space and they are
fixed in accordance with manufacturers’ instructions; and c.
the sensor in ceiling-mounted devices is between 25mm and 600mm below
the ceiling (25-150mm in the case of heat detectors or heat alarms).
Note: This guidance applies to ceilings that are predominantly flat
and horizontal.
1.16 It should be possible to reach the smoke alarms to carry out
routine maintenance, such as testing and cleaning, easily and safely.
For this reason smoke alarms should not be fixed over a stair or any
other opening between floors.
1.17 Smoke alarms should not be fixed next to or directly above
heaters or air-conditioning outlets. They should not be fixed in
bathrooms, showers, cooking areas or garages, or any other
place where steam, condensation or fumes could give false alarms.
1.18 Smoke alarms should not be fitted in places that get very hot
(such as a boiler room) or very cold (such as an unheated porch).
They should not be fixed to surfaces which are normally much warmer or
colder than the rest of the space, because the temperature difference
might create air currents which move smoke away from the unit.

Power supplies
1.19 The power supply for a smoke alarm system should be derived from
the dwellinghouse’s mains electricity supply. The mains supply to the
smoke alarm(s) should comprise a single independent circuit at the
dwellinghouse’s main distribution board (consumer unit) or a single
regularly used local lighting circuit. This has the advantage that the
circuit is unlikely to be disconnected for any prolonged period. There
should be a means of isolating power to the smoke alarms without
isolating the lighting
1.20 The electrical installation should comply with Approved Document
P (Electrical safety).

1.21 Any cable suitable for domestic wiring may be used for the power
supply and interconnection to smoke alarm systems. It does not need
any particular fire survival properties except in large houses (BS
5839-6:2004 specifies fire resisting cables for Grade A and B
systems). Any conductors used for interconnecting alarms (signalling)
should be readily distinguishable from those supplying mains power,
e.g. by colour coding.

Note:
Mains-powered smoke alarms may be interconnected using radio-links,
provided that this does not reduce the lifetime or duration of any
standby power supply below 72 hours. In this case, the smoke alarms
may be connected to separate power circuits (see paragraph 1.19)

1.22 Other effective options exist and are described in BS 5839-1:2002
and BS 5839-6:2004. For example, the mains supply may be reduced
to extra low voltage in a control unit incorporating a standby
trickle-charged battery, before being distributed at that voltage to
the alarms.

Design and installation of systems
1.23 It is essential that fire detection and fire alarm systems are
properly designed, installed and maintained. Where a fire alarm system
is installed, an installation and commissioning certificate should be
provided. Third party certification schemes for fire protection
products and related services are an effective means of providing the
fullest possible assurances, offering a level of quality, reliability
and safety.

1.24
A requirement for maintenance cannot be made as a condition of passing
plans by the Building Control Body. However, the attention of
developers and builders is drawn to the importance of providing the
occupants with information on the use of the equipment, and on its
maintenance (or guidance on suitable maintenance contractors). See
paragraph 0.11.
Note:

BS 5839-1 and BS 5839-6 recommend that occupiers should receive the
manufacturers’ instructions concerning the operation and maintenance
of the alarm system.

Good grief you poor innocent soul. Half of our lot cannot tell the
difference between carbon monoxide and smoke alarms.
Brian

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"Brian Reay" wrote in message
news
On 17/09/2018 23:12, Peter Parry wrote:
On Mon, 17 Sep 2018 21:12:48 +0100, "Jim GM4DHJ ..."
wrote:

are optical smoke alarms better for less false alarms than ionising
ones...in practice I mean ? .....

No. Neither have significant false alarm rates. Both however can
suffer nuisance alarms, these are not false alarms but real alarms
produced by non- dangerous activities such as steam from a bathroom
or overheated toast.

Optical suffer more from steam, ionisation from the combustion
products of things like singed toast. Used and sited properly neither
should have a significant nuisance alarm rate (unless of course you
are prone to overheating toast with the toaster is in the bathroom
sink while you are taking a shower).


There are different types, at least 3, of detectors which are recommended
for different rooms/areas for just the reasons you say. Placing the right
one in the right location/checking it has been done is the kind of thing
I'd expect a competent Building Inspector to be able to do. May be a call
to the local council?

--

Smile for the camera ;-)
https://www.youtube.com/watch?v=HxyL2_38EsQ
Remarkable Coincidences:
The Stock Market Crashes of 1929 and 2008 happened on the same
date in October. In Oct 1907, a run on the Knickerbocker Trust
Company led to the Great Depression.

don't worry about it ...brian reay tries everything to try and belittle
people he doesn't like....he is a sad case

"Brian Gaff" wrote in message
news
Good grief you poor innocent soul. Half of our lot cannot tell the
difference between carbon monoxide and smoke alarms.
Brian

--
----- --
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please
Note this Signature is meaningless.!
"Brian Reay" wrote in message
news
On 17/09/2018 23:12, Peter Parry wrote:
On Mon, 17 Sep 2018 21:12:48 +0100, "Jim GM4DHJ ..."
wrote:

are optical smoke alarms better for less false alarms than ionising
ones...in practice I mean ? .....

No. Neither have significant false alarm rates. Both however can
suffer nuisance alarms, these are not false alarms but real alarms
produced by non- dangerous activities such as steam from a bathroom
or overheated toast.

Optical suffer more from steam, ionisation from the combustion
products of things like singed toast. Used and sited properly neither
should have a significant nuisance alarm rate (unless of course you
are prone to overheating toast with the toaster is in the bathroom
sink while you are taking a shower).


There are different types, at least 3, of detectors which are recommended
for different rooms/areas for just the reasons you say. Placing the right
one in the right location/checking it has been done is the kind of thing
I'd expect a competent Building Inspector to be able to do. May be a call
to the local council?

--

Smile for the camera ;-)
https://www.youtube.com/watch?v=HxyL2_38EsQ
Remarkable Coincidences:
The Stock Market Crashes of 1929 and 2008 happened on the same
date in October. In Oct 1907, a run on the Knickerbocker Trust
Company led to the Great Depression.

"Peter Parry" wrote in message
...
On Mon, 17 Sep 2018 21:12:48 +0100, "Jim GM4DHJ ..."
wrote:

are optical smoke alarms better for less false alarms than ionising
ones...in practice I mean ? .....

No. Neither have significant false alarm rates. Both however can
suffer nuisance alarms, these are not false alarms but real alarms
produced by non- dangerous activities such as steam from a bathroom
or overheated toast.

Optical suffer more from steam, ionisation from the combustion
products of things like singed toast. Used and sited properly neither
should have a significant nuisance alarm rate (unless of course you
are prone to overheating toast with the toaster is in the bathroom
sink while you are taking a shower).


It is mainly cooking and toast that do it...I bought an optical one
yesterday and will replace the ionising one in the ground floor hall and see
if we can cut down the false alarms .....probably get one to replace the one
at the static caravan should work better there .....I found the ionising one
at the caravan to be a god send when we had a leak of raw gas which set it
off good style which was surprising as propane is heavier than air and I
have no idea how it set off an ceiling mounted optical smoke alarm .....
but glad it did

On 18/09/2018 08:09, Jim GM4DHJ ... wrote:
"Peter Parry" wrote in message
...
On Mon, 17 Sep 2018 21:12:48 +0100, "Jim GM4DHJ ..."
wrote:

are optical smoke alarms better for less false alarms than ionising
ones...in practice I mean ? .....

No. Neither have significant false alarm rates. Both however can
suffer nuisance alarms, these are not false alarms but real alarms
produced by non- dangerous activities such as steam from a bathroom
or overheated toast.

Optical suffer more from steam, ionisation from the combustion
products of things like singed toast. Used and sited properly neither
should have a significant nuisance alarm rate (unless of course you
are prone to overheating toast with the toaster is in the bathroom
sink while you are taking a shower).


It is mainly cooking and toast that do it...I bought an optical one
yesterday and will replace the ionising one in the ground floor hall and see
if we can cut down the false alarms .....probably get one to replace the one

If you are getting regular false alarms like that then you aren't
cooking your food you are burning it to a cinder with associated risks
of making carcinogenic compounds like acrylamide in the resulting char.

https://www.food.gov.uk/safety-hygiene/acrylamide

at the static caravan should work better there .....I found the ionising one
at the caravan to be a god send when we had a leak of raw gas which set it
off good style which was surprising as propane is heavier than air and I
have no idea how it set off an ceiling mounted optical smoke alarm .....
but glad it did




--
Regards,
Martin Brown

If you are getting regular false alarms like that then you aren't
cooking your food you are burning it to a cinder with associated risks of
making carcinogenic compounds like acrylamide in the resulting char.

I blame the wife...

On 18/09/2018 09:24, Martin Brown wrote:

If you are getting regular false alarms like that then you aren't
cooking your food you are burning it to a cinder with associated risks
of making carcinogenic compounds like acrylamide in the resulting char.


An alternative hypothesis is that he is cooking food with flavours which
he enjoys, despite such warnings, in order to enhance his quality of
life and increasing the sum total of his quality-adjusted life years
(QALYs)[1]. I'd call that sensible DIY QALY control.

He may also be doing so in full knowledge that the warnings about
acrylamide are based largely on the precautionary principle.

And when you say "burning it to a cinder" he - like me - might say
"triggering the Maillard reaction".

Now I'm off to have another strong coffee. Full of acrylamide. But
where even the FDA don't think a warning is needed. As confirmed only
last month in a much more even comment on the issue.

https://www.fda.gov/NewsEvents/Newsr.../ucm618883.htm




[1] for this purpose I use QALY to mean not just a year in "perfect
health" but also with desired level of happiness.

--
Robin
reply-to address is (intended to be) valid

"Robin" wrote in message
...
On 18/09/2018 09:24, Martin Brown wrote:

If you are getting regular false alarms like that then you aren't cooking
your food you are burning it to a cinder with associated risks of making
carcinogenic compounds like acrylamide in the resulting char.


An alternative hypothesis is that he is cooking food with flavours which
he enjoys, despite such warnings, in order to enhance his quality of life
and increasing the sum total of his quality-adjusted life years
(QALYs)[1]. I'd call that sensible DIY QALY control.

He may also be doing so in full knowledge that the warnings about
acrylamide are based largely on the precautionary principle.

talk as if i'm not here why don't you...patronising...tee hee


And when you say "burning it to a cinder" he - like me - might say
"triggering the Maillard reaction".

Now I'm off to have another strong coffee. Full of acrylamide. But where
even the FDA don't think a warning is needed. As confirmed only last
month in a much more even comment on the issue.

https://www.fda.gov/NewsEvents/Newsr.../ucm618883.htm




[1] for this purpose I use QALY to mean not just a year in "perfect
health" but also with desired level of happiness.

I don't drink coffee.......

No but one added thing to take into account. Most people tend to site them
on the ceiling. This is not a good idea if you have to climb to change a
battery or stop it sounding cos you burned the toast. I have one half way up
the stairs which may mean it gets more toast falls alarms but is easy to
shut up without getting a ladder or falling.
Brian

--
----- --
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please
Note this Signature is meaningless.!
"Peter Parry" wrote in message
...
On Mon, 17 Sep 2018 21:12:48 +0100, "Jim GM4DHJ ..."
wrote:

are optical smoke alarms better for less false alarms than ionising
ones...in practice I mean ? .....

No. Neither have significant false alarm rates. Both however can
suffer nuisance alarms, these are not false alarms but real alarms
produced by non- dangerous activities such as steam from a bathroom
or overheated toast.

Optical suffer more from steam, ionisation from the combustion
products of things like singed toast. Used and sited properly neither
should have a significant nuisance alarm rate (unless of course you
are prone to overheating toast with the toaster is in the bathroom
sink while you are taking a shower).

On 18/09/2018 16:29, Brian Gaff wrote:
No but one added thing to take into account. Most people tend to site them
on the ceiling. This is not a good idea if you have to climb to change a
battery or stop it sounding cos you burned the toast. I have one half way up
the stairs which may mean it gets more toast falls alarms but is easy to
shut up without getting a ladder or falling.

A suitable length stick will allow a reset without climbing. Can't
change a battery that way though. The ones the fire brigade fit for the
elderly in Manchester are one time usage with no replaceable parts
(which seems a shame to me). They are scrapped typically every 4 years.

The only time mine or the Village Hall ones false alarm is on days like
today when real smoke from someone's coal fire nearby gets wafted into
the building through an open door. The main mode of failure is a low
battery alarm panic in the middle of a cold winter's night consisting of
an annoying loud chirp every couple of minutes. Too loud to ignore.

--
Regards,
Martin Brown

"Brian Gaff" wrote in message
news
No but one added thing to take into account. Most people tend to site them
on the ceiling. This is not a good idea if you have to climb to change a
battery or stop it sounding cos you burned the toast. I have one half way
up the stairs which may mean it gets more toast falls alarms but is easy
to shut up without getting a ladder or falling.

Corse a well designed one would have a remote
or be able to be turned off using your phone.

"Peter Parry" wrote in message
...
On Mon, 17 Sep 2018 21:12:48 +0100, "Jim GM4DHJ ..."
wrote:

are optical smoke alarms better for less false alarms than ionising
ones...in practice I mean ? .....

No. Neither have significant false alarm rates. Both however can
suffer nuisance alarms, these are not false alarms but real alarms
produced by non- dangerous activities such as steam from a bathroom
or overheated toast.

Optical suffer more from steam, ionisation from the combustion
products of things like singed toast. Used and sited properly neither
should have a significant nuisance alarm rate (unless of course you
are prone to overheating toast with the toaster is in the bathroom
sink while you are taking a shower).

On Thu, 20 Sep 2018 04:41:36 +1000, cantankerous trolling senile geezer Rot
Speed blabbered, again:


No but one added thing to take into account. Most people tend to site them
on the ceiling. This is not a good idea if you have to climb to change a
battery or stop it sounding cos you burned the toast. I have one half way
up the stairs which may mean it gets more toast falls alarms but is easy
to shut up without getting a ladder or falling.

Corse a well designed one would have a remote
or be able to be turned off using your phone.

Of course normally evolved humans aren't much interested in getting every
new electronic feature in every new-fangled electronic gadget, you
brain-dead senile self-admitted consumer of every electronic ****!

--
Bill Wright to Rot Speed:
"That confirms my opinion that you are a despicable little ****."
MID:

Corse a well designed one would have a remote
or be able to be turned off using your phone.

Of course normally evolved humans aren't much interested in getting every
new electronic feature in every new-fangled electronic gadget,

must be me and my nokia 1100 you are refering to ......

Corse a well designed one would have a remote
or be able to be turned off using your phone.

would that work with my nokia 1100 ?.....

On 17/09/2018 21:12, Jim GM4DHJ ... wrote:
are optical smoke alarms better for less false alarms than ionising
ones...in practice I mean ? .....

Which Sept 2018 has a review of Smoke Alarms.
(Sorry, can't seem to find a pdf of it to post: will keep looking)

"Allan" wrote in message
...
On 17/09/2018 21:12, Jim GM4DHJ ... wrote:
are optical smoke alarms better for less false alarms than ionising
ones...in practice I mean ? .....

Which Sept 2018 has a review of Smoke Alarms.
(Sorry, can't seem to find a pdf of it to post: will keep looking)


good man

On 17/09/18 21:12, Jim GM4DHJ ... wrote:
are optical smoke alarms better for less false alarms than ionising
ones...in practice I mean ? .....



I would read the Ei Aico website - lots of deployment info on there.

I have their alarms - mains interlinked: CO, heat, mostly ionising but
possibly one optical (I forget).

The only false alarms I have every had we

1) Hoovering out the dust - stops as soon as hoover removed;

2) Heat gun paint stripping - impressive, no visible smoke;

3) Soldering water pipes.

4) Couple of times cooking smokey dishes (searing beef) - heat detector
locally, so must have got to the hall alarm...

I'd say they do a remarkable job with very little nuisance.

Well, ionising ones tend to spot invisible things if they change the
conductivity of an ionised area in the sensor, but optical ones presumably
have the band set to attempt to detect most smoke particles. I guess in the
end it depends what is burning. I'd suspect that tiny toast burns might
produce larger particles than something like a smouldering item, but I've
not tested it.
Presumably all must conform to some kind of standard and how can one tell
if smoke is from burned toast or a real fire in the end?
Brian

--
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The Sofa of Brian Gaff...

Blind user, so no pictures please
Note this Signature is meaningless.!
"Jim GM4DHJ ..." wrote in message
...
are optical smoke alarms better for less false alarms than ionising
ones...in practice I mean ? .....

my new one says TOAST on the box

A"Jim GM4DHJ ..." wrote in message
...
my new one says TOAST on the box

sorry TOAST PROOF ......

"Brian Gaff" wrote in message
news
Well, ionising ones tend to spot invisible things if they change the
conductivity of an ionised area in the sensor, but optical ones presumably
have the band set to attempt to detect most smoke particles. I guess in
the end it depends what is burning. I'd suspect that tiny toast burns
might produce larger particles than something like a smouldering item, but
I've not tested it.
Presumably all must conform to some kind of standard and how can one tell
if smoke is from burned toast or a real fire in the end?

But it is useful to distinguish between steam which can
come from such innocuous sources as the shower or
the vegys being cooked, and something like burnt toast.

And the best ones give an earlier warning of something
that has melted like an electrical cord which hasn’t yet
actually set fire to the curtains or carpet etc too.

"Jim GM4DHJ ..." wrote in message
...
are optical smoke alarms better for less false alarms than ionising
ones...in practice I mean ? .....

On Thu, 20 Sep 2018 04:40:17 +1000, cantankerous trolling senile geezer Rot
Speed blabbered, again:

Well, ionising ones tend to spot invisible things if they change the
conductivity of an ionised area in the sensor, but optical ones presumably
have the band set to attempt to detect most smoke particles. I guess in
the end it depends what is burning. I'd suspect that tiny toast burns
might produce larger particles than something like a smouldering item, but
I've not tested it.
Presumably all must conform to some kind of standard and how can one tell
if smoke is from burned toast or a real fire in the end?

But it is useful to distinguish between steam which can
come from such innocuous sources as the shower or
the vegys being cooked, and something like burnt toast.

And the best ones give an earlier warning of something
that has melted like an electrical cord which hasn¢t yet
actually set fire to the curtains or carpet etc too.

You just HAVE to keep smartassing, eh, you disgusting senile wisenheimer?
LOL

--
Marland addressing bull****ting senile Rot:
"Stay in your wet paper bag you thick twit."
MID:

Jim GM4DHJ ... wrote

are optical smoke alarms better for less false
alarms than ionising ones...in practice I mean ? .....

Depends on what is producing your false alarms.

Burnt toast is different to steam etc.

On Wed, 19 Sep 2018 09:26:02 +1000, cantankerous trolling senile geezer Rot
Speed blabbered, again:

are optical smoke alarms better for less false
alarms than ionising ones...in practice I mean ? .....

Depends on what is producing your false alarms.

Burnt toast is different to steam etc.

He was given already all the right answers, senile Rot! So what makes you
think it is important that YOU still have to have your say, you abnormal
85-years-old Ozzie *******?

--
FredXX to Rot Speed:
"You are still an idiot and an embarrassment to your country. No wonder
we shippe the likes of you out of the British Isles. Perhaps stupidity
and criminality is inherited after all?"
Message-ID:

"Peeler" wrote in message
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On Wed, 19 Sep 2018 09:26:02 +1000, cantankerous trolling senile geezer
Rot
Speed blabbered, again:

are optical smoke alarms better for less false
alarms than ionising ones...in practice I mean ? .....

Depends on what is producing your false alarms.

Burnt toast is different to steam etc.

He was given already all the right answers, senile Rot! So what makes you
think it is important that YOU still have to have your say, you abnormal
85-years-old Ozzie *******?

that is not very nice

On Wed, 19 Sep 2018 12:08:41 +0100, Jim GM4DHJ ... wrote:

Depends on what is producing your false alarms.

Burnt toast is different to steam etc.

He was given already all the right answers, senile Rot! So what makes you
think it is important that YOU still have to have your say, you abnormal
85-years-old Ozzie *******?

that is not very nice

Right!

https://www.youtube.com/watch?v=mcDgOGC5Lcc

good tester...