PIREP--CO Experts low level carbon monoxide detector

Many of us cold-weather pilots worry about carbon monoxide in the cabin,
especially in winter. After using the "dot-that-changes
color-on-a-piece-of-cardboard" carbon monoxide detectors for the last 9
years, we decided to look at the new battery-operated detectors.

Last year I made a foray into this field by buying a Wal-Mart home model.
It turned out to be too big for use in the plane, and had an alarm threshold
that was set too high. I got the distinct feeling that we would be dead long
before the alarm ever sounded. After tripping over it for a few months, it
migrated into our home -- and we went back to the "dot-on-the-cardboard"
model.

When www.Aeromedix.com started advertising their "CO Experts" low level
monitor, it sounded like just what we were looking for. While it's still
not tiny, it's much smaller than the home model, and it displays carbon
monoxide levels at a MUCH lower level, without sounding a stupid alarm until
the levels become worrisome.

When they offered it on sale for "only" $99, I bought one. We've been
flying behind it now for several weeks of cool-to-cold weather, and here are
our results:

1. Convenience. I briefly considered mounting it to the ceiling with
double-back tape, but I feared it wouldn't stick for long. Thus, I settled
on mounting it just to the left of the pilot's yoke, on the side panel. To
hold it there I simply installed a longer screw in the side upholstery, and
"hung" the unit from the screw. (It has a screw-mount hole on the
backside.) This has proven satisfactory -- it's a nice looking unit, it's
not in the way, and it's clearly visible for both pilot and copilot. It
can also be easily removed in the summer, if desired. (Which we won't do,
for reasons listed below.)
Rating: Fair. (I'd rather it was smaller.)

2. Usability. Controls on the unit -- which runs on a single 9 volt
battery -- consist of a digital LCD readout, and a test/reset button.
Before each flight we push the test button, which sounds an alarm tone and
runs the unit through a diagnostic routine. It's simple, easy, and requires
nothing more than a single push of a single button to assure that it's
working.
Rating: Excellent.

3. Sensitivity. On take off, at high angles of attack, it's not unusual to
smell exhaust in our plane. The 235 is capable of some fairly impressive
climb rates, especially when lightly loaded, and I like to get high as
quickly as possible -- so suffice it to say that we routinely smell exhaust
during the climbout.

I've always wondered how much CO we were getting in the cabin when this
happened, but the "dots-on-the-cardboard" never registered anything.

The CO Expert immediately came to life during climbout, showing a read-out
of from 10 to 17 parts per million. (The FAA minimum is 50, so this is not
alarming.) Once we leveled out, the smell went away, and the CO Expert went
blank. The unit updates every SIX seconds, so it reacts very quickly to
changes, and it appears to be every bit as sensitive as they say it is.
Rating: Good.

4. Results. In cruise flight, we register no CO in the cabin.
Surprisingly, our highest readouts have been observed upon throttling back
to enter the pattern -- with the heater OFF. Levels as high as 34 ppm have
been observed (still well below the FAA threshold of 50 ppm) on downwind in
this flight regime, which surprised us.

Again, the angle of attack is different during slow flight, so the exhaust
is apparently being drawn into the fresh air ducts (perhaps up on the tail,
according the Cherokee Pilots Association) during this stage of flight.

Interestingly, turning the heater on (and thus pressurizing the cabin a bit)
caused CO levels to drop back to zero. Nice to know our heat exchanger is
evidently not cracked!

5. Conclusion. The unit works as advertised, and has given us confidence
that our aircraft is safe. We are confident that the CO monitor will give
us ample warning of high CO levels in the cabin should a heat exchanger
crack, or some other leakage develop.

Since the highest levels of CO have been observed with the heater off, it's
easy to see that carbon monoxide isn't just a cold-weather issue. I think,
however, that you won't see potentially dangerous levels of CO in the cabin
unless you're getting it through a bad heat exchanger, or a scat tubing
leak -- but since the unit takes up so little space we'll probably just
leave it in the plane all the time.

Overall Rating: Excellent. I'd buy it again.

See it at http://makeashorterlink.com/?E3E8243E9
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

Pretty much the same experience we had.

I would add that support is excellent. Ours went bad slightly out of the
guarantee period and they replaced it at no cost.

I filled in the back of ours inside the raised edge with plastic sheet and
then put the hook side of Velcro tape all over the back. Our upholstery
type is such that it will just stick to the side of the cabin wherever we
put it.

--

Roger Long



"Jay Honeck" wrote in message
newsPtqd.410498$wV.201320@attbi_s54...
Many of us cold-weather pilots worry about carbon monoxide in the cabin,
especially in winter. After using the "dot-that-changes
color-on-a-piece-of-cardboard" carbon monoxide detectors for the last 9
years, we decided to look at the new battery-operated detectors.

Last year I made a foray into this field by buying a Wal-Mart home model.
It turned out to be too big for use in the plane, and had an alarm
threshold that was set too high. I got the distinct feeling that we would
be dead long before the alarm ever sounded. After tripping over it for a
few months, it migrated into our home -- and we went back to the
"dot-on-the-cardboard" model.

When www.Aeromedix.com started advertising their "CO Experts" low level
monitor, it sounded like just what we were looking for. While it's still
not tiny, it's much smaller than the home model, and it displays carbon
monoxide levels at a MUCH lower level, without sounding a stupid alarm
until the levels become worrisome.

When they offered it on sale for "only" $99, I bought one. We've been
flying behind it now for several weeks of cool-to-cold weather, and here
are our results:

1. Convenience. I briefly considered mounting it to the ceiling with
double-back tape, but I feared it wouldn't stick for long. Thus, I
settled on mounting it just to the left of the pilot's yoke, on the side
panel. To hold it there I simply installed a longer screw in the side
upholstery, and "hung" the unit from the screw. (It has a screw-mount
hole on the backside.) This has proven satisfactory -- it's a nice
looking unit, it's not in the way, and it's clearly visible for both pilot
and copilot. It can also be easily removed in the summer, if desired.
(Which we won't do, for reasons listed below.)
Rating: Fair. (I'd rather it was smaller.)

2. Usability. Controls on the unit -- which runs on a single 9 volt
battery -- consist of a digital LCD readout, and a test/reset button.
Before each flight we push the test button, which sounds an alarm tone and
runs the unit through a diagnostic routine. It's simple, easy, and
requires nothing more than a single push of a single button to assure that
it's working.
Rating: Excellent.

3. Sensitivity. On take off, at high angles of attack, it's not unusual
to smell exhaust in our plane. The 235 is capable of some fairly
impressive climb rates, especially when lightly loaded, and I like to get
high as quickly as possible -- so suffice it to say that we routinely
smell exhaust during the climbout.

I've always wondered how much CO we were getting in the cabin when this
happened, but the "dots-on-the-cardboard" never registered anything.

The CO Expert immediately came to life during climbout, showing a read-out
of from 10 to 17 parts per million. (The FAA minimum is 50, so this is
not alarming.) Once we leveled out, the smell went away, and the CO
Expert went blank. The unit updates every SIX seconds, so it reacts very
quickly to changes, and it appears to be every bit as sensitive as they
say it is.
Rating: Good.

4. Results. In cruise flight, we register no CO in the cabin.
Surprisingly, our highest readouts have been observed upon throttling back
to enter the pattern -- with the heater OFF. Levels as high as 34 ppm
have been observed (still well below the FAA threshold of 50 ppm) on
downwind in this flight regime, which surprised us.

Again, the angle of attack is different during slow flight, so the exhaust
is apparently being drawn into the fresh air ducts (perhaps up on the
tail, according the Cherokee Pilots Association) during this stage of
flight.

Interestingly, turning the heater on (and thus pressurizing the cabin a
bit) caused CO levels to drop back to zero. Nice to know our heat
exchanger is evidently not cracked!

5. Conclusion. The unit works as advertised, and has given us confidence
that our aircraft is safe. We are confident that the CO monitor will give
us ample warning of high CO levels in the cabin should a heat exchanger
crack, or some other leakage develop.

Since the highest levels of CO have been observed with the heater off,
it's easy to see that carbon monoxide isn't just a cold-weather issue. I
think, however, that you won't see potentially dangerous levels of CO in
the cabin unless you're getting it through a bad heat exchanger, or a scat
tubing leak -- but since the unit takes up so little space we'll probably
just leave it in the plane all the time.

Overall Rating: Excellent. I'd buy it again.

See it at http://makeashorterlink.com/?E3E8243E9
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

In article pPtqd.410498$wV.201320@attbi_s54,
Jay Honeck wrote:

When www.Aeromedix.com started advertising their "CO Experts" low level
[snip]
The unit updates every SIX seconds, so it reacts very quickly to

I ran into a guy with the cowling off his 182 the other day. He had
gotten one of those units and discovered that his heater was producing
some CO. He was very happy about the ability to measure low levels (not
just thresholds) and move it around the cabin to find where the CO was
coming in.

Oddly his exhaust had pressure tested good (and this is on a freshly
overhauled engine) so just as a precaution he was replacing all the
vent related SCAT tubing.

--
Ben Jackson

http://www.ben.com/

Ben,

I agree with Jay, the CO Experts unit is excellent. I've had mine for
some time now, I have it in my flight bag in the house as a detector
and then it goes with me in the airplane.

Using it I've found that a number of airplanes have CO in the cabin
but not from a bad heater. The exhaust travels along the belly and
enters near the aft portion of the tailcone. The airflow within the
tailcone is forward, so the CO comes into the cabin. In one of the
airplanes I fly the baggage compartment contstantly has a measurable
level of CO. If the heater and all the vents are off, there is CO in
the entire passenger cabin. With the heater and/or vents on, the CO
is pushed aft and remains only in the baggage area.

Now I'm looking for a way to seal the baggage curtain to keep the air
from the tailcone from coming into the cabin.

All the best,
Rick

(Ben Jackson) wrote in message news:eZuqd.112409$5K2.80452@attbi_s03...
In article pPtqd.410498$wV.201320@attbi_s54,
Jay Honeck wrote:

When www.Aeromedix.com started advertising their "CO Experts" low level
[snip]
The unit updates every SIX seconds, so it reacts very quickly to

I ran into a guy with the cowling off his 182 the other day. He had
gotten one of those units and discovered that his heater was producing
some CO. He was very happy about the ability to measure low levels (not
just thresholds) and move it around the cabin to find where the CO was
coming in.

Oddly his exhaust had pressure tested good (and this is on a freshly
overhauled engine) so just as a precaution he was replacing all the
vent related SCAT tubing.

If you are using autofuel, the fumes from the autofuel will turn the
cardboard detectors black over time.

Jay Honeck wrote:
Many of us cold-weather pilots worry about carbon monoxide in the cabin,
especially in winter. After using the "dot-that-changes
color-on-a-piece-of-cardboard" carbon monoxide detectors for the last 9
years, we decided to look at the new battery-operated detectors.

john smith wrote:

If you are using autofuel, the fumes from the autofuel will turn the
cardboard detectors black over time.

You shouldn't be getting gasoline fumes in the cabin.

George Patterson
My mother is 82 and she still doesn't need glasses.
Drinks right out of the bottle.

"Jay Honeck" wrote in message
newsPtqd.410498$wV.201320@attbi_s54...
Many of us cold-weather pilots worry about carbon monoxide in the cabin,
especially in winter. After using the "dot-that-changes
color-on-a-piece-of-cardboard" carbon monoxide detectors for the last 9
years, we decided to look at the new battery-operated detectors.


I settled
on mounting it just to the left of the pilot's yoke, on the side panel.

Jay Honeck

That is the correct place for a CO detector, as CO is heavier than air. On
the ceiling, unless it is in the airstream that is carrying the bad air in,
it is possible that the alarm would not sound.

That's what I have read, anyway. g
--
Jim in NC


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Morgans wrote:
"Jay Honeck" wrote in message
newsPtqd.410498$wV.201320@attbi_s54...

Many of us cold-weather pilots worry about carbon monoxide in the cabin,
especially in winter. After using the "dot-that-changes
color-on-a-piece-of-cardboard" carbon monoxide detectors for the last 9
years, we decided to look at the new battery-operated detectors.



I settled
on mounting it just to the left of the pilot's yoke, on the side panel.


Jay Honeck


That is the correct place for a CO detector, as CO is heavier than air.

Carbon is mass 12, oxygen is 16, so CO has a mass of about 28 g/mole
as compared to the major components of air: O2 at 32 g/mole and N2
at 28 g/mole. So it should mix very well. If it's being brought in
by the heater then it would have a slight tendency to rise initially
until it cools to the ambient temperature in the cabin.

"Jay Honeck" wrote in message news:pPtqd.410498$wV.201320@attbi_s54...
Many of us cold-weather pilots worry about carbon monoxide in the cabin,
especially in winter. After using the "dot-that-changes
color-on-a-piece-of-cardboard" carbon monoxide detectors for the last 9
years, we decided to look at the new battery-operated detectors.

Last year I made a foray into this field by buying a Wal-Mart home model.
It turned out to be too big for use in the plane, and had an alarm threshold
that was set too high.

That's a common problem in the U.S. Fire departments complained about
too many call outs so the feds limit the thresholds. I bought mine
from a firm in the U.K. and have been very happy. I did have a real
life CO emergency and was very happy to have had it. I was surprised
that...

1) Turning off the heater DID NOT lower the CO level enough for
survival. With the heater on I was getting about 1500 ppm near my
head. With it off I was still getting around 800ppm.

2) Opening the pilot window did make a big difference, bringing my
near head level to about 200ppm (that is within Cal OSHA's tolerance
for an 8 hour work day).

3) This happened after take off at night in dark IMC. I heard the
alarm. I'm sure there would have been no way I'd have noticed a
sticker changing color while coordinating with ATC in dark IMC.

4) With the digital gauge I was able to quantify my problem. Without
it, I'm not sure what I would have done. I wouldn't have had any way
to determine the level of severity.

-Robert

"Robert M. Gary" wrote in message om...
snip

3) This happened after take off at night in dark IMC. I heard the
alarm. I'm sure there would have been no way I'd have noticed a
sticker changing color while coordinating with ATC in dark IMC.

4) With the digital gauge I was able to quantify my problem. Without
it, I'm not sure what I would have done. I wouldn't have had any way
to determine the level of severity.

-Robert



What did you do? Did you request a return to airport?