CO Monitors

[Awqward]

The Aeromedix unit looks remarkably similar to the Firehawk CO7BD unit I found on the UK Amazon store for a lot less than $199....

http://www.amazon.co.uk/MONOXIDE-DETECTOR-DIGITAL-DISPLAY-WARRANTY/dp/B00F984BMQ/ref=sr_1_29?ie=UTF8&qid=1419796346&sr=8-29&keywords=Co+detector+lcd+display#productDetails

Although interestingly I can't find it in the US Amazon site....possibly due to non-compliance with UL as mentioned above...

[larryb]

I have my aeromedix unit attached to the pedestal next to the flap indicator. The u it works great. It usually says 25ppm on the ground during run up and 0 I. Cruise.

[carusoam]

21 UK Pounds, but no LCD display.

Make sure you get the same sensitivity with that as well, A.

They appear to have their cases built by the same moulder...

LarryB, what did you use for mounting?

Best regards,

-a-

[Awqward]

Maybe the link is screwed up....£24 with the LCD display....looks identical to the Aeromedix unit....but I gues it is possible that they have different internals / programming...

Edit: I tracked down the specs for the Firehawk unit and it does not sound an alarm unless 30ppm > 2 hrs... 50ppm > 40 mins etc....so clearly NOT the same as the Aeromedix....

[aviatoreb]

I not suggesting not having a CO level detector, I certainly have one. What I am saying is that with an exhaust content around 400ppm you will be overcome very quickly. With an exhaust content of 10ppm you will not and have plenty of time to react. Perhaps you can perform some math and explain to us how that although the CO exhaust content is only 10 ppm the content in the cabin will ever be higher than that? OSHA considers 50 ppm average per 8 hr day to be acceptable.

 

Ah - I was just remarking - for all of us not just for you N601RX that we should carry a CO monitor even if a LOP advocate.

 

Is it really true that in the exhaust stack the reading is 10ppm LOP?  Where is that measured?  I would not trust that this reading will stay steady with some of the systems failing.  I don't know the general details of the problem well enough to understand the assumptions to do any math, but on the face of it, I do not expect any concentration of that once it gets to the cabin.

 

Anyway, I am speaking from the standpoint of a failure - then all bets are off and the CO monitor helps find the failure.

 

Most LOP operators still climb ROP.  A full rich climb and a cracked exhaust stack can still push enough bad air into the cabin to make a problem pretty quickly.

 

Actually, about 3 years ago I detected a cracked exhaust stack by my CO monitor.  It was an early and mild crack and the CO readings were not yet dangerous - but they had changed from standard readings on recent flights, so I had an inspection of exhaust system done and sure enough there was a new crack.  We had it repaired.

[carusoam]

Interesting graph...

What it doesn't show is how LOP the engine is compared to the conversion of CO to CO2.

We know where peak is. That is minimum O2 available to make the conversion possible.

How LOP would we need to be to have excess O2 for highest CO conversion? 10°F, 50°F or 100°F?

Fast, Efficient AND low CO were not in my mission statement...

Safety is... Aeromedix seems to be a solution for the unusual high CO situation...

Thank you MS for bringing this out in the open and following up with great ideas.

Best regards,

-a-

[aviatoreb]

I use one of these tiny digital units.

 

http://www.aircraftspruce.com/catalog/pspages/co300.php

 

I have it velcro'ed adjacent to the sun visor above the pilots head.

[Hector]

Attached is a graph of CO content vs mixture ratio. There is a hugh difference in CO content for full rich and lop. About 450 ppm vs somewhere around 10ppm

Good info. At a minimum it tells me that if I ever detect high CO levels in the cockpit I should lean as much as possible until I can safely get on the ground. My carbureted C will not run completely LOP, but I can get 3 of the 4 cylinders LOP before it starts running rough. That would hopefully buy me enough time.

[Bennett]

I've previously related why I am so concerned about CO in the cockpit. I added a panel mounted Guardian CO detector unit - mounted in the pedestal, with an annunciator in the upper left section of my panel (the orange square). I also had the alerter wired into the audio panel. I do know about the maintenance costs, and I will have the unit serviced at my next annual at LASAR. I don't want to cut costs where CO is concerned.

[carusoam]

Bennet has the ability to add the next level.

The one I would never be able to think of on my own.

Thank you, Sir,

Best regards,

-a-

[larryb]

I mounted it with high strength double sided foam tape.

Sent from my iPad using Tapatalk

[N601RX]

The CO curve appears to be pretty flat once you go past peak. This also goes along with Carbon monoxide being product of incomplete combustion of fuel due to insufficient oxygen to complete oxidation of CO2. LOP always has excess oxygen in the mixture and the CO content will be low. The graphs I posted earlier show air/ fuel ratio, but more familiar numbers can be added to them by looking in the POH. My POH shows the following as a data point.

Best Power Setting at 7500

2700 rpm

23"

70.5 lbs fuel per hour

With a best power ratio of about 13:1 you are using about 916 lbs of air per hr. ( 70.5. X 13= 916)

Leaning only the mixture the air flow is mostly unchanged so a 14.7:1 mixture will give about 62.3. lbs of fuel per hr. 916/14.7=62.3

Leaning to a 16:1 mixture will result in about 57.3 lbs fuel hr.

The above pounds per hr are then converted to the following gph which we are very familiar with.

13:1 ratio =12.2gph

14.7:1 ratio=10.7gph

16:1ratio= 9.8 gph (which is very close to most of our favorite lop setting for a lycoming 4 banger)

[carusoam]

I'm following along, now....

It is challenging to contemplate air used in pounds per hour...!

CO poisoning is terrible at all levels because the speed at which it is released takes so long. It has the tendency to build up in the body over time...

Best regards,

-a-

[N601RX]

Yes it leaves very slowly, Best to keep it out of your system. According to the newest OSHA rules, 35ppm weighted average is acceptable for an 8 hr shift and doesn't cause any clinical symptoms or long term damage. As a second point they say a concentration of 200ppm is only safe for 5 minutes. Many of the NTSB reports you read are scary and the occupants appear to be incapacited very quickly.

[aviatoreb]

Attached is a graph of CO content vs mixture ratio. There is a hugh difference in CO content for full rich and lop. About 450 ppm vs somewhere around 10ppm

 

Its a really cool graph.  Where did you find it?  Thanks for the further interpretation.

 

I was adamant that a CO monitor should be carried anyway - but getting past that - is this chart saying that 10ppm of CO is coming out of the tail pipe?  SO we can happily breath straight from the tailpipe without CO danger?

[carusoam]

Rumor has it that the closed garage is a tougher way to go, since the lates version of catalytic converters and OBD2 have become the norm...

Computer controlled electronic ignition combined with cats and sensors this might be true...?

Some cities in California (San Fran) still require vents for home garages...?

It is not normal on the east coast to run an engine in a closed room...?

Best regards,

-a-

[TWinter]

Had this for about a year..pricey for a two year life, but I guess I've spent more on things that won't save my life. These are nice and will clip or hang just about anywhere.

 

Sporty's has them. $149

[N601RX]

Eric,

According to the papers it was measured inside the tailpipe. There are several graduate research papers and numerous other online data about CO content in exhaust of combustion engines. Some of the groups started capturing exhaust by using it to inflate plastic bags which were then analyzed in a laboratory. This was very slow and then they began using electronic sensors and stated the results were comparable.

I'm sure there are other nasty things in exhaust you don't need to breath, but the CO contents appears to be well below the OSHA limits when lop. The O2 content would be very low if breathing pure exhaust. Looking at the 200 ppm limit osh has set for 5 minutes exposure it looks like you could be incapacitated in only a couple of minutes with levels in the 300 to 400ppm range. For that you would need an audible alarm that sounds immediately. Luckily most all cracks and leaks start small and spread over time if ignored. Altitude can increase the affects on a person.

Mike

[RobertGary1]

With the heat on, you're probably going to read around 1500ppm. At least that's my experience. I suppose the crack could be worse and you could get more.

[kmyfm20s]

Well I have had the Co-Experts low level Co monitor for a week now and can say it is sensitive and a quality little Co monitor. It works as advertised and my highest reading so far has been 20ppm, I was behind a turboprop. When I taxi behind many planes I get a momentary readings. I'm glad to say that it has not gone off when using my heater. I was worried after I order it after I read the dimensions on the AeroMedics website but I'm happy to inform you that it was wrong it easily fits in the palm of my hand, it is not 10"x6" and does not weight 10oz. I am happy with the purchase and my first alert is now at home next to my water heaters:)

[Bob_Belville]

I just ordered/received a UEI UTLC11. $79 from Zoro. At that price I'm anxious to see if it will be appropriate for a plane. It is sold for commercial/industrial use. Looks like it ought to be much better than the disposable cards. We'll see.

 

http://www.ueitest.com/products/utl-brand/utlc11

 

Anyone familiar with this type detector?

[Marauder]

I just ordered/received a UEI UTLC11. $79 from Zoro. At that price I'm anxious to see if it will be appropriate for a plane. It is sold for commercial/industrial use. Looks like it ought to be much better than the disposable cards. We'll see.

http://www.ueitest.com/products/utl-brand/utlc11

Anyone familiar with this type detector?

Let us know how it works for you Test Pilot Bob!

[aviatoreb]

I just ordered/received a UEI UTLC11. $79 from Zoro. At that price I'm anxious to see if it will be appropriate for a plane. It is sold for commercial/industrial use. Looks like it ought to be much better than the disposable cards. We'll see.

 

http://www.ueitest.com/products/utl-brand/utlc11

 

Anyone familiar with this type detector?

 

Yeah - very curious!  Does it stay on if you turn it on - or is it for probe testing - meaning you turn it on and it tells you current reading and then turns off?

[Mooneymite]

I just ordered/received a UEI UTLC11. $79 from Zoro. At that price I'm anxious to see if it will be appropriate for a plane. It is sold for commercial/industrial use. Looks like it ought to be much better than the disposable cards. We'll see.

 

http://www.ueitest.com/products/utl-brand/utlc11

 

Anyone familiar with this type detector?

Where have you set the alarm level?

[Marauder]

Yeah - very curious! Does it stay on if you turn it on - or is it for probe testing - meaning you turn it on and it tells you current reading and then turns off?

I didn't catch late earlier. It has a 15 duty cycle.

"Powered by batteries, Auto power off in 15 min. under non-operation."