CO Concentrations in Cabin

I purchased a C0 Experts Model 2002 about 1 month ago (it is quite
precise and I am generally pleased with it). When I am climbing out
from take-off, I am experiencing relatively high readings of CO, on the
order of 30 Parts Per Million (PPM). This only lasts about 20 minutes
or so. At cruise, it drops to below 10 PPM (considered normal).

(a) Does anyone else have any hard data about their CO concentration
levels in various phases of flight?

(b) I have read that anything above 10 PPM should be checked by an A&P,
but I have read elsewhere that something like 30PPM for short periods is
not a big deal. Are there any medical-types out there that can weigh in
on this issue?

On Thu, 01 Apr 2004 23:31:51 -0600, "O. Sami Saydjari"
wrote:

I purchased a C0 Experts Model 2002 about 1 month ago (it is quite
precise and I am generally pleased with it). When I am climbing out
from take-off, I am experiencing relatively high readings of CO, on the
order of 30 Parts Per Million (PPM). This only lasts about 20 minutes
or so. At cruise, it drops to below 10 PPM (considered normal).

(a) Does anyone else have any hard data about their CO concentration
levels in various phases of flight?

(b) I have read that anything above 10 PPM should be checked by an A&P,
but I have read elsewhere that something like 30PPM for short periods is
not a big deal. Are there any medical-types out there that can weigh in
on this issue?

I had a home type CO monitor supposedly sensitive to 1-3ppm. It would
occasionally read 25ppm if I was on the ground and behind another a/c. It
would rarely alarm on the ground when I was not behind another a/c. I
suspected that had to do with wind blowing exhaust in a particular
direction.

It always dropped to undetectable levels during the takeoff roll.

30ppm for a few minutes won't damage you, but I'd sure have your exhaust
system checked by a competent technician.


Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

On Thu, 01 Apr 2004 23:31:51 -0600, "O. Sami Saydjari"
wrote:

I purchased a C0 Experts Model 2002 about 1 month ago (it is quite
precise and I am generally pleased with it). When I am climbing out
from take-off, I am experiencing relatively high readings of CO, on the
order of 30 Parts Per Million (PPM). This only lasts about 20 minutes
or so. At cruise, it drops to below 10 PPM (considered normal).

(a) Does anyone else have any hard data about their CO concentration
levels in various phases of flight?

(b) I have read that anything above 10 PPM should be checked by an A&P,
but I have read elsewhere that something like 30PPM for short periods is
not a big deal. Are there any medical-types out there that can weigh in
on this issue?

If you haven't already, it might be interesting to try a couple of
test climbs with cabin heat & defrost on and off. If the PPM went up
when using the heat, I would definitely have an A&P look at your
exhaust/heating exchange system.

On the ground, at 70PPM for 20 minutes you will start to experience a
headache. 30PPM @ 20 minutes should not be a problem unless you're
climbing to ~ 8000 or are a smoker or suffer from some respiratory
malady or are in a constant state of inactivity (a lazy *******) . I
would first look real hard for any openings in your firewall to seal
and from there go to any exhaust compromise. I would then have the
ignition and carburetion systems checked to determine why you're
burning so dirty.

For those who aren't able to think, although 30 ppm at the exhaust
pipe isn't high, that much leak into the cabin indicates a bigger
problem at the dump. And as CO is a byproduct of the incomplete
combustion of a fossil fuel, it indicates something amiss in the
cylinders.

On Thu, 01 Apr 2004 23:31:51 -0600, "O. Sami Saydjari"
wrote:

I purchased a C0 Experts Model 2002 about 1 month ago (it is quite
precise and I am generally pleased with it). When I am climbing out
from take-off, I am experiencing relatively high readings of CO, on the
order of 30 Parts Per Million (PPM). This only lasts about 20 minutes
or so. At cruise, it drops to below 10 PPM (considered normal).

(a) Does anyone else have any hard data about their CO concentration
levels in various phases of flight?

(b) I have read that anything above 10 PPM should be checked by an A&P,
but I have read elsewhere that something like 30PPM for short periods is
not a big deal. Are there any medical-types out there that can weigh in
on this issue?

I've used one of the digitals for a long time and they really help
keep an eye on whats going on. It's helped me spot exhaust
problems I would have otherwise missed. Some observations
based on my experience:

* I typically see it in the 20s on the ground .. maybe a tad higher
if I'm positioned such that the exhaust is entering the outside air vent.
In the air seldom more than 10ppm.

* When I was having some trouble with cracked risers I'd see
it in the upper 30s to 40s.. on the ground and in the air. While a
higher reading isn't always alarming on the ground if it stays that
way in the air there's a leak somewhere.

* If it goes up when you turn on the cabin heat have the muffler
checked inside the shroud.

* Sometimes getting the seam between the muffler and risers
to seal can be a challenge. I've found in those instances I'd see
a reading in the teens in the air from it seeping into the cabin
from the engine compartment.

As a comparison .. in the winter I often use a propane construction
heater in the hangar if I have something to do on the plane. When
I do I also keep the CO meter handy. I'll see consistent readings in
the 30s. While I've never had any headaches or anything doing this
after a couple hours my eyes will start to burn a little and I generally
limit this to a couple hours at a time.

These meters when used regularly will really help you spot trends
that are out of the ordinary for your plane that you wouldn't otherwise
catch.



"Stu Gotts" wrote in message
...
On the ground, at 70PPM for 20 minutes you will start to experience a
headache. 30PPM @ 20 minutes should not be a problem unless you're
climbing to ~ 8000 or are a smoker or suffer from some respiratory
malady or are in a constant state of inactivity (a lazy *******) . I
would first look real hard for any openings in your firewall to seal
and from there go to any exhaust compromise. I would then have the
ignition and carburetion systems checked to determine why you're
burning so dirty.

For those who aren't able to think, although 30 ppm at the exhaust
pipe isn't high, that much leak into the cabin indicates a bigger
problem at the dump. And as CO is a byproduct of the incomplete
combustion of a fossil fuel, it indicates something amiss in the
cylinders.

On Thu, 01 Apr 2004 23:31:51 -0600, "O. Sami Saydjari"
wrote:

I purchased a C0 Experts Model 2002 about 1 month ago (it is quite
precise and I am generally pleased with it). When I am climbing out
from take-off, I am experiencing relatively high readings of CO, on the
order of 30 Parts Per Million (PPM). This only lasts about 20 minutes
or so. At cruise, it drops to below 10 PPM (considered normal).

(a) Does anyone else have any hard data about their CO concentration
levels in various phases of flight?

(b) I have read that anything above 10 PPM should be checked by an A&P,
but I have read elsewhere that something like 30PPM for short periods is
not a big deal. Are there any medical-types out there that can weigh in
on this issue?

If you haven't already, it might be interesting to try a couple of
test climbs with cabin heat & defrost on and off. If the PPM went up
when using the heat, I would definitely have an A&P look at your
exhaust/heating exchange system.

Good suggestion. I should have mentioned that I tried that and that it
seems independent of heating and defronsting settings.

-Sami

On Thu, 01 Apr 2004 23:31:51 -0600, "O. Sami Saydjari"
wrote:

I purchased a C0 Experts Model 2002 about 1 month ago (it is quite
precise and I am generally pleased with it). When I am climbing out
from take-off, I am experiencing relatively high readings of CO, on the
order of 30 Parts Per Million (PPM). This only lasts about 20 minutes
or so. At cruise, it drops to below 10 PPM (considered normal).

(a) Does anyone else have any hard data about their CO concentration
levels in various phases of flight?

(b) I have read that anything above 10 PPM should be checked by an A&P,
but I have read elsewhere that something like 30PPM for short periods is
not a big deal. Are there any medical-types out there that can weigh in
on this issue?

In Canada you can work in up to 35ppm for 8hours. 30 ppm isn't a big
deal for a short time but you might want to check your firewall for
leaks.

On Sat, 03 Apr 2004 00:58:01 GMT, (Drew
Dalgleish) wrote:

In Canada you can work in up to 35ppm for 8hours. 30 ppm isn't a big
deal for a short time but you might want to check your firewall for
leaks.

Remember, that's at ground level!

On my Arrow, normal cabin airflow is through heat or ventilation ducts
in front of the cabin, exiting underneath the plane. If the heat and
vents are off, there can be enough air leaks around the door, etc to
reverse that flow, which can pick up exhaust underneath the airplane.

This situation has been improved a lot with the new door seals from
Dick Russ.