CO indicators
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6643
- Posts: 2482
- Joined: Tue May 01, 2018 7:00 am
- Name: John C
- Location: KLCI, NH
- Aircraft Type: 1946 C140/C90
- Occupation-Interests: A&P, semi-retired
- Contact:
Re: CO indicators
Remember that cold draft on your neck in the winter? Exhaust can travel down the belly of the plane to the tail and enter there (rudder cables?) and then back up through the tail cone to the passenger cabin. Opening the wing root vents should help raise the pressure in front and stem the flow, but it doesn't feel too good in winter...
John Cooper
www.skyportservices.net
www.skyportservices.net
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a64pilot
- Posts: 319
- Joined: Sat Aug 29, 2020 8:41 pm
- Name: Jody
- Aircraft Type: C-140
- Occupation-Interests: A&P former IA, Retired test pilot
- Contact:
Re: CO indicators
You guys may be interested in this thread.
https://mooneyspace.com/topic/21247-moo ... alks-away/
Sensorcom is or was offering a discount, I’ll try to get that code
https://mooneyspace.com/topic/21247-moo ... alks-away/
Sensorcom is or was offering a discount, I’ll try to get that code
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gryph0n
- Posts: 31
- Joined: Mon Dec 09, 2019 12:38 pm
- Name: Steve S British Columbia Repr
- Location: CAK3 Delta Airpark, BC
- Aircraft Type: 1948 C-140 O200
- Occupation-Interests:
- Contact:
Re: CO indicators
My experience-
I was getting very high sporadic readings from my Sentry ADSB device (70-80ppm). My A&P (Kate K at Resnick Airport, NY) did a pressurization test, where she hooked a shop vacuum up to the exhaust outlet with duct tape, turned it on reverse, and then sprayed the exhaust system with soapy water, then looked for bubbles indicating a leak. There were leaks detected at some joints in one muffler, so we replaced that side. There were also leaks detected at several of the cylinder exhaust ports, so my A&P reconditioned them by shaving them down flat with a special tool, and replaced the gaskets. She repeated the soap test and there were no leaks detected.
I got a CO Experts CO detector, which works great. It is very sensitive and about the size of an egg. It has a super loud alarm chirp, and It can be used as a sniffer. Even without any leaks in the exhaust system, I was still getting the following readings in the cabin
Winter
Takeoff 17 ppm, Initial Level Off 22-32ppm, Cruise 7-13ppm
Summer
Takeoff 8 ppm, Initial Level Off 15ppm, Cruise 0ppm
There were no differences between having cabin heat on or off, however I found that if I sealed off the opening into the rear fuselage cone with tape, and scrupulously sealed all the door/ window openings, CO readings would drop about 10ppm in either season.
Steve
I was getting very high sporadic readings from my Sentry ADSB device (70-80ppm). My A&P (Kate K at Resnick Airport, NY) did a pressurization test, where she hooked a shop vacuum up to the exhaust outlet with duct tape, turned it on reverse, and then sprayed the exhaust system with soapy water, then looked for bubbles indicating a leak. There were leaks detected at some joints in one muffler, so we replaced that side. There were also leaks detected at several of the cylinder exhaust ports, so my A&P reconditioned them by shaving them down flat with a special tool, and replaced the gaskets. She repeated the soap test and there were no leaks detected.
I got a CO Experts CO detector, which works great. It is very sensitive and about the size of an egg. It has a super loud alarm chirp, and It can be used as a sniffer. Even without any leaks in the exhaust system, I was still getting the following readings in the cabin
Winter
Takeoff 17 ppm, Initial Level Off 22-32ppm, Cruise 7-13ppm
Summer
Takeoff 8 ppm, Initial Level Off 15ppm, Cruise 0ppm
There were no differences between having cabin heat on or off, however I found that if I sealed off the opening into the rear fuselage cone with tape, and scrupulously sealed all the door/ window openings, CO readings would drop about 10ppm in either season.
Steve