Seen these around at all ?..........

[Guest Maj Millard]

A friends aircraft has a very neat little Carbon monoxide detector plugged into the power socket. It is one of the nicest little units I have come across, and I would like to find a supplier.

 

When plugged in a green light is aluminated, and a red light blinks if Carbon monoxide is detected. If only a small amount the red light blinks slowly, if a lot it blinks rapidly. It also has a push to test button. Have googled the brand name but nothing came up.......any help appreciated..........Maj.....

 

 

 

 

 

 

 

[Head in the clouds]

Punch this into your search bar and you'll find lots of references - HIH.

 

https://www.google.com.au/search?q=techpro+co+protector&oq=techpro+co+protector&aqs=chrome..69i57.9000j0j4&sourceid=chrome&espv=210&es_sm=122&ie=UTF-8#es_sm=122&espv=210&q=techpro+co+detector

 

 

[M61A1]

http://www.prnewswire.com/news-releases/techpro-electronics-launches-coprotectortm---the-worlds-1st-electrochemical-carbon-monoxide-detector-specially-designed-for-use-in-cars-57109587.html

[Guest Andys@coffs]

BTW important to note.....These electronic CO detectors have a limited lifetime sensor, in general they are only good for 5years then ned to be replaced.

 

The better quality ones also have a LED 2 or 3 digit display that show the measured PPM which can be enough to give you confidence that it is working where as a non flashing LED tells me it either hasn't found anything...or it isn't working.....

 

There is a manufacturer of these in the states that from memory are in the big spruce catalogues, where given the 5yr limitation on the sensor they have a trade in offer for a replacement device and the cost of that isn't the same as buying a new one.....but freight from AU may well make up the difference....

 

What ever you use it needs to have a good visual alarm...a beeping piezo alarm in a cockpit with the hp generator at TO revs will struggle to be heard. A really bright flashing LED that is focused via a moveable neck to hit you right in the eye will do it

 

Andy

 

 

[rankamateur]

They were released in Jan 2009 so now have 2 months to run before replacement. wonder does the five years count on the shelf or only in use? If business has been slow, new ones might soon be expired.

 

 

[Downunder]

I use one of these http://www.aircraftspruce.com/catalog/pspages/llifecodetectors.php?clickkey=6773

 

Suits my needs......

 

 

[Old Koreelah]

One of the first effects of CO poisoning is loss of colour vision, so those colour-change cards are probably a waste of cockpit space.

 

I installed an electronic domestic detector which runs on a 9V battery and reads CO in ppm. The only times there is a leak into the cockpit is when I fully close the cowl flaps. The engine cowl is made from composite. A fortunate side-effect is that when there is a leak the distinctive smell of cooking Klegecell permeates the cockpit. If the CO meter ever fails, a cockpit leak should not go un-noticed.

 

 

[Methusala]

I was flying my Volksplane back from Tumut some years back when I noticed that the round pill in a plastic bubble started to turn black. I had climbed about 3000ft out of the valley and so did not want to return particularly. It was about 70 nm to my base which normally would take a little over an hour to go. However I encountered a stiff breeze on the nose which slowed progress to barely 40kts. I spent the next hour doing mental arithmetic, touching the end of my nose, feeling my fingertips for any numbness and hoping that the forest in the distance which marked home base would hurry up and arrive, When I landed I found that the sharp 180 deg bends on the exhaust headers had corroded through. This is the only time that I have had a CO scare, but the cheap chemical indicator worked a treat. Don

 

 

[Guest Maj Millard]

Thanks for the help folks ..............................Cheers Maj....

 

 

[Dafydd Llewellyn]

BTW important to note.....These electronic CO detectors have a limited lifetime sensor, in general they are only good for 5years then ned to be replaced.

 

Andy

Thanks for that piece of info, Andy - I was not aware of that little quirk.

 

 

[Guest Andys@coffs]

In doing some more investigation its not so much that the sensor becomes no good, but rather the way they work is that they generate a voltage output that is linearly proportional to the PPM reading where the voltage, at least on the sensors I looked at on the weekend, were about 1mV per ppm so pretty small voltage deltas...

 

The 5 year limit is manufacturer imposed and represents the time that they are prepared to accept before a recalibration is needed.

 

Some manufacturers sell cans of air with defined PPM concentrations of CO in them so that people can validate that their device is still accurate (at least at that CO concentration). You put your device turned on, in a ziplock baggy fill it with the canned test air, and if it displays the cans PPM then good to go for another 12 months.... But of course while Yanks can buy the test can online to test their device we in Australia cant because the can is "Dangerous Cargo"......perhaps someone in Aus sells it...but I suppose in typical fashion it will be 3x the cost....

 

Andy

 

 

[Dafydd Llewellyn]

The one I have is simply a warning device, which is of the "none/some/ LOOK OUT!" type, sold by Global Aviation. It wasn't what I really wanted, which was a calibrated instrument reading in ppm, that I could use to give CAR 35 approvals (I have previously used the old Drager type, which uses a glass tube with crystals in, you use one tube each time you make a measurement - but calibration is not an issue with them). A lot of local councils have one. I've investigated one accident which was a mid-air break-up, almost certainly due to pilot incapacitation due to CO; it's more of a danger than people commonly realise. The damn fool medical examiner dismissed it on the basis that such indications as were forensically possible did not indicate a lethal CO level - completely ignoring the fact that the ground can get in the way long before the pilot dies from excess carboxyhaemoglobin.

 

 

[frank marriott]

I've got a digital readout one, I replace the battery every 100hrly [about $3], works fine - at least so far. I'm pretty sure I purchased it from Ian here at Clear Prop.

 

Readout plus flashing red light and audio warning.

 

 

[jetjr]

I imported some of these and they are excellent, you can buy direct from manufacturer but have to buy 10+. Ian sold some of them, support Ian if he can supply.

 

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

 

New battery once/yr.

 

Very sensitive and picks up low level long term danger and alarms for this too

 

CO is culmulative, a low dose for hours is just as bad as sudden higher level.

 

LOUD and flashing light as well as digital readout

 

 

[Dafydd Llewellyn]

ERhmm . . . The FAR 23 limit is 50 ppm (same in most if not all certification standards); anything above 25 ppm will give you a cracking headache. However, it looks like a good form of cockpit alarm device. Who can calibrate them, and wot does it cost?

 

Wonder what these cost: http://www.draeger.com/sites/assets/PublishingImages/Products/cin_pac_7000/Attachments/pac_7000_pi_9046061_en.pdf - I'd want the one with 35 ppm & 50 ppm alarms.

 

 

[jetjr]

Some interesting stuff here

 

http://www.detectcarbonmonoxide.com/co-health-risks/

 

NIST test done back to manufacturer, calibration done with special test canister, surely someone here can supply or offer testing, maybe scuba dive people?

 

These are very small return may not be a big deal.

 

I believe can be alarm tested with match/candle and unit both under sealed cover??

 

Instructions seem to indicate that if the unit returns to zero its OK. No mention of life of sensor. Guess a calibration would pick up a fault?

 

 

[Dafydd Llewellyn]

The danger from CO in an aircraft can be more subtle than that article indicates. In the accident I described, it seems likely that the pilot realised he had a problem, and closed the throttle to slow down (that was definite, both from witness reports and the position of the vernier throttle control from the wreckage), so he could open the canopy. In wrestling with the canopy, he may have hyperventilated (happens much more readily if you are suffering from the effects of CO) and lost consciousness. The aircraft rolled inverted and headed for the centre of the Earth, and simply came apart from sheer overspeed (after descending about one mile from its cruise level). This requires less than half the lethal concentration of CO in the bloodstream, from what I was able to dig up. CO is BAD NEWS.

 

 

[Gnarly Gnu]

anything above 25 ppm will give you a cracking headache.

Is that the same for everyone? A couple of us had an excess CO situation in the workshop one day due to lack of ventilation whilst using a big diesel burner and I can't say there was any headache, we both got extremely sleepy and groggy. We were even aware it could happen (planned to switch off the heater shortly) but it snuck up before we realised that was the scary part.

 

 

[Dafydd Llewellyn]

Is that the same for everyone? A couple of us had an excess CO situation in the workshop one day due to lack of ventilation whilst using a big diesel burner and I can't say there was any headache, we both got extremely sleepy and groggy. We were even aware it could happen (planned to switch off the heater shortly) but it snuck up before we realised that was the scary part.

I don't know how much people vary; I got a splitting headache from CO from a VW Beetle heater, once, without any other noticable symptoms. Didn't have the benefit of a CO detector to tell what dosage I was getting. Later, when doing CO checks in aircraft, I found the headache coming on at around 25 ppm. Maybe I've become sensitized; definitely don't rely on a headache to give warning. I go looking if there's more than about 10 ppm, nowadays. It's generally worse when the door seals etc are leaky, because that lowers the pressure in the cabin, and then exhaust gets sucked in via the openings in the fuselage that usually exist for the empennage controls. Open-cockpit aircraft are often surprisingly bad, for this reason; I once tested an Ag-Cat with an open joyride cockpit where the hopper used to be; it was within limits, but not by much. The Cherokee 140 I had used to suck exhaust into the cabin in a sideslip, via the holes for the main wing spar. A very minor change in the exhaust outlet location can make a big change in CO level, so I consider a detector a necessity.

 

 

[Old Koreelah]

Very difficult to seal an exhaust system and a cabin. One of the few advantages of having the engine behind you.

 

My system sure needs a professional's touch to seal the leaks where the engine pipes enter the muffler, unless someone can recommend a reliable sealant.

 

That job has now shot up my list of priorities.

 

 

[Downunder]

I've used a auto muffler putty but it doesn't handle the heat on my exhaust very well and becomes flaky.

 

So I'm in the market too for a suitable sealant...

 

 

[Dafydd Llewellyn]

Don't use it on the exhaust; use it on the firewall.

 

 

[Old Koreelah]

If I can't find a flexible sealant I may have to get a proper welder to extend the short collars that the exhaust pipes loosely fit into (modified Jabiru) and clamp them around the pipe to get a better seal.

 

The problem with Carbon Monoxide is that blood loves it, and will absorb a couple of hundred times as much CO as Oxygen.

 

That means even a small amount leaking into the cabin can be dangerous.

 

 

[rankamateur]

The problem with Carbon Monoxide is that blood loves it, and will absorb a couple of hundred times as much CO as Oxygen.That means even a small amount leaking into the cabin can be dangerous.

More to the point the blood loves it 250 times more than it loves oxygen, so the concentration of oxygen has to be increased to more than 250 times the concentration of the carbon monoxide to cause the CO to be pushed off the active sites on the heamoglobin, so opening the vents a bit wider doesn't really reverse the damage, when you are already feeling symptoms.

 

 

[Dafydd Llewellyn]

I suggest that you work on the assumption that the cowl will at some time contain CO; and concentrate on preventing that CO from entering the cabin. Leakage in the firewall is target No. 1; there are various semi-flexible goos available for that.

 

Target No. 2 is any exhaust-muff cabin heater. They are a CO incident waiting to happen. There are no really simple alternatives; if you operate in a cold climate, maybe flying boots? And a really good CO detector.

 

Target No. 3 is, improve the cabin door seals, and ensure sufficient freash air is available from a clean source, so that air is trying to escape from the cabin, not being sucked into it.

 

Obviously, there are many ramifications to these general principles; they are pretty obvious, so I don't want to enter into a long dissertation on them