We have a fairly old CO alarm which has never gone off (well, it
shouldn't, should it!?) and self-tests fine when you press the button on
the front.

Does that necessarily mean it's working fine as regards measuring CO
levels though? I don't see how...

I suppose more for interest's sake, I was wondering about setting up a
test - short of firing up the barbeque in a closed garage, can anybody
suggest an easy way to see if it does actually respond to increased CO
levels? Obviously not possible to do any sort of calibrated check
without the necessary equipment.

David

On Nov 5, 12:23*pm, Lobster wrote:
We have a fairly old CO alarm which has never gone off (well, it
shouldn't, should it!?) and self-tests fine when you press the button on
the front.

Does that necessarily mean it's working fine as regards measuring CO
levels though? I don't see how...

I suppose more for interest's sake, I was wondering about setting up a
test - short of firing up the barbeque in a closed garage, can anybody
suggest an easy way to see if it does actually respond to increased CO
levels? *Obviously not possible to do any sort of calibrated check
without the necessary equipment.

David

Hold a lit candle under it?

Jonathan

On Thu, 05 Nov 2009 12:23:46 +0000, Lobster wrote:

We have a fairly old CO alarm which has never gone off (well, it
shouldn't, should it!?) and self-tests fine when you press the button on
the front.

How old is it? They usually have an expiry date, although at least some
will warn you when that is reached. If it's near it, you might as well
just get a new one!

--
Use the BIG mirror service in the UK:
http://www.mirrorservice.org

Jonathan wrote:
On Nov 5, 12:23 pm, Lobster wrote:
We have a fairly old CO alarm which has never gone off (well, it
shouldn't, should it!?) and self-tests fine when you press the button on
the front.

Does that necessarily mean it's working fine as regards measuring CO
levels though? I don't see how...

I suppose more for interest's sake, I was wondering about setting up a
test - short of firing up the barbeque in a closed garage, can anybody
suggest an easy way to see if it does actually respond to increased CO
levels? Obviously not possible to do any sort of calibrated check
without the necessary equipment.

Hold a lit candle under it?

Hmm, just tried shutting in in a biscuit tin with a lit candle until the
latter was suffocated (yes, I'm bored).

No alarm. Should there have been?

Discuss...!

David

On 5 Nov, 12:23, Lobster wrote:
We have a fairly old CO alarm which has never gone off

Does that necessarily mean it's working fine as regards measuring CO
levels though? I don't see how...

AIUI, current production alarms attempt to detect sensor end-of-life
and raise a warning then anyway. However I would follow manufacturer's
lifetime guidance (usually 5 or 6 years, not long). The colour-change
disks only last a year.

Easiest portable CO source I've found is a lump of barbecue charcoal
in a tin. However this just checks function and doesn't give much
faith in calibration.

Bob Eager wrote:
On Thu, 05 Nov 2009 12:23:46 +0000, Lobster wrote:

We have a fairly old CO alarm which has never gone off (well, it
shouldn't, should it!?) and self-tests fine when you press the button on
the front.

How old is it? They usually have an expiry date, although at least some
will warn you when that is reached. If it's near it, you might as well
just get a new one!

Ooh, so it does! Let's just say it expired, ahem, a while ago. Will
certainly replace it, though am still interested in the original query!

Thanks
David

On Thu, 05 Nov 2009 12:23:46 +0000, Lobster
wrote:


We have a fairly old CO alarm which has never gone off (well, it
shouldn't, should it!?) and self-tests fine when you press the button on
the front.

Does that necessarily mean it's working fine as regards measuring CO
levels though? I don't see how...

Unlike smoke detectors, CO sensors in the alarms have a very limited
life - often no more than 2 years, newer ones can be up to 5 years.
The self test does not test the sensor.

On Thu, 05 Nov 2009 12:50:31 +0000, Lobster wrote:

Bob Eager wrote:
On Thu, 05 Nov 2009 12:23:46 +0000, Lobster wrote:

We have a fairly old CO alarm which has never gone off (well, it
shouldn't, should it!?) and self-tests fine when you press the button
on the front.

How old is it? They usually have an expiry date, although at least some
will warn you when that is reached. If it's near it, you might as well
just get a new one!

Ooh, so it does! Let's just say it expired, ahem, a while ago. Will
certainly replace it, though am still interested in the original query!

Glad to help!

BTW, let's hope they get the postal strike called off for tomorrow, and
you might then get my parcel before the weekend...

--
Use the BIG mirror service in the UK:
http://www.mirrorservice.org

Bob Eager wrote:
On Thu, 05 Nov 2009 12:50:31 +0000, Lobster wrote:

Bob Eager wrote:
On Thu, 05 Nov 2009 12:23:46 +0000, Lobster wrote:

We have a fairly old CO alarm which has never gone off (well, it
shouldn't, should it!?) and self-tests fine when you press the button
on the front.
How old is it? They usually have an expiry date, although at least some
will warn you when that is reached. If it's near it, you might as well
just get a new one!
Ooh, so it does! Let's just say it expired, ahem, a while ago. Will
certainly replace it, though am still interested in the original query!

Glad to help!

BTW, let's hope they get the postal strike called off for tomorrow, and
you might then get my parcel before the weekend...

Indeed, looking forward to it - and fiddling about with a laserjet fuser
should be more productive use of my time than pratting about with an old
CO monitor! Thanks again...

David

Andy Dingley wrote:
On 5 Nov, 12:23, Lobster wrote:
We have a fairly old CO alarm which has never gone off

Does that necessarily mean it's working fine as regards measuring CO
levels though? I don't see how...

AIUI, current production alarms attempt to detect sensor end-of-life
and raise a warning then anyway. However I would follow manufacturer's
lifetime guidance (usually 5 or 6 years, not long). The colour-change
disks only last a year.

Easiest portable CO source I've found is a lump of barbecue charcoal
in a tin. However this just checks function and doesn't give much
faith in calibration.

Good idea - we'll be laying a fire tonight anyway, so will find a lump
of charcoal to burn and stick it in my biscuit tin. Sounds highly
likely that the sensor's gone anyway but am interested to try it!

David

Lobster wrote:
We have a fairly old CO alarm which has never gone off (well, it
shouldn't, should it!?) and self-tests fine when you press the button on
the front.

Does that necessarily mean it's working fine as regards measuring CO
levels though? I don't see how...

I suppose more for interest's sake, I was wondering about setting up a
test - short of firing up the barbeque in a closed garage, can anybody
suggest an easy way to see if it does actually respond to increased CO
levels? Obviously not possible to do any sort of calibrated check
without the necessary equipment.

David
Get a smoker to breathe on it?

Peter Scott

On 5 Nov, 12:23, Lobster wrote:
I was wondering about setting up a
test - short of firing up the barbeque in a closed garage, can anybody
suggest an easy way to see if it does actually respond to increased CO
levels?

BES sell an aerosol for testing CO alarms (Detectagas, P/N 12556).
Around £7.

CRB

In article ,
Lobster wrote:
Hmm, just tried shutting in in a biscuit tin with a lit candle until the
latter was suffocated (yes, I'm bored).

No alarm. Should there have been?

I tried the same with the wideband O2 sensor I was about to fit to the old
car - nothing. The way you do a rough check they're working is by
squirting some butane into them. The reading then goes off the scale.

--
*The man who fell into an upholstery machine is fully recovered*

Dave Plowman London SW
To e-mail, change noise into sound.

I suppose more for interest's sake, I was wondering about setting up a
test - short of firing up the barbeque in a closed garage, can anybody
suggest an easy way to see if it does actually respond to increased CO
levels? Obviously not possible to do any sort of calibrated check
without the necessary equipment.

This was discussed on this group a while ago. I think the suggested
solution was leave it in a garage with a car engine running. But then there
were a lot of retards posting on that thread.

I dare say Google Groups will unearth this gem of a thread if you look hard
enough ;-)

Al.

p.s. Just Buy A New One You Tightwad ;-)

On 5 Nov 2009 13:30:40 GMT, Bob Eager wrote:

On Thu, 05 Nov 2009 12:50:31 +0000, Lobster wrote:

Bob Eager wrote:
On Thu, 05 Nov 2009 12:23:46 +0000, Lobster wrote:

We have a fairly old CO alarm which has never gone off (well, it
shouldn't, should it!?) and self-tests fine when you press the button
on the front.

How old is it? They usually have an expiry date, although at least some
will warn you when that is reached. If it's near it, you might as well
just get a new one!

Ooh, so it does! Let's just say it expired, ahem, a while ago. Will
certainly replace it, though am still interested in the original query!

Glad to help!

BTW, let's hope they get the postal strike called off for tomorrow, and
you might then get my parcel before the weekend...

The Postal strike has been called off until after New Year

In article ,
Al wrote:
This was discussed on this group a while ago. I think the suggested
solution was leave it in a garage with a car engine running. But then
there were a lot of retards posting on that thread.

Would have to be an old car. Modern ones have catalytic convertors - and
one of their functions is to convert CO.

--
*I never drink anything stronger than gin before breakfast *

Dave Plowman London SW
To e-mail, change noise into sound.

On 5 Nov 2009 20:37:18 GMT, Al wrote:
I suppose more for interest's sake, I was wondering about setting up a
test - short of firing up the barbeque in a closed garage, can anybody
suggest an easy way to see if it does actually respond to increased CO
levels? Obviously not possible to do any sort of calibrated check
without the necessary equipment.

This was discussed on this group a while ago. I think the suggested
solution was leave it in a garage with a car engine running. But then there
were a lot of retards posting on that thread.

I dare say Google Groups will unearth this gem of a thread if you look hard
enough ;-)

Al.

p.s. Just Buy A New One You Tightwad ;-)

The same question pertains to a new one. If yo're going to trust your
life to a CO detector (even a new, shop-bought one), it would be nice
to have confidence that the detector actually works. I'ts not as if you
could take it back for a replacement if you're dead :-)

"Dave Plowman (News)" wrote in message
...
In article ,
Al wrote:
This was discussed on this group a while ago. I think the suggested
solution was leave it in a garage with a car engine running. But then
there were a lot of retards posting on that thread.

Would have to be an old car. Modern ones have catalytic convertors - and
one of their functions is to convert CO.

CO2 will also kill you.
It just doesn't poison the blood the same way.

On Thu, 05 Nov 2009 12:23:46 +0000, Lobster
wrote:

I suppose more for interest's sake, I was wondering about setting up a
test - short of firing up the barbeque in a closed garage, can anybody
suggest an easy way

IIRC the sensor can be permanently damaged by exposure to high levels
of CO. Perhaps the 'test aerosol' suggested earlier would be best.