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OXYMETER

RV-4

Well Known Member
Hello All

A little while ago I bought an oxygen system just in case I needed to fly at a higher altitude but I didn't buy the oxymeter at that time..

For you guys flying with oxygen, is there a good oxymeter that you will recommend I buy so that I can keep an eye on my oxygen saturation level if need be??

Thanks

Bruno
 
Look on ebay. Quality varies considerably but they all seem to be made in China. You will see the same oximeter with different labels with wildly varying prices.
 
Thank you for the replies guys, it is appreciated

I just look at the Walmart Drugstore website and they have a few to choose from so I should be able to get one locally that will do the job

Cheers

Bruno
 
have no specific brand to recommend, just a short note...

this week we brought my 7 up to FL210 (DA was 23000 ft). we had independent oxygen and an oxymeter. my oxygen did not work properly and my buddy tested our blood's oxygen concentration. his was around 99% up there. my was 80%, which is well within the dangerous area.

strange thing was that he said that i would behave not normal, but for me everything felt ok. just back on the ground i realized that something was very wrong with me at altitude. no big deal as he was able to fly us home.

what i learned is that i would never fly above FL120 or so without an oxymeter. these small and cheap devices are a very good thing. especcially when you're the only one riding the aircraft.
 
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Buy one with large numbers on the display. Some of the oximeters on Amazon have display with too much information all packed into a small screen. Also I prefer one that you can read when you look straight down at your hand. The Braun linked above is the screen format I prefer.
 
Those Amazon pulse oximeters are fine for home use. The different brands all use the same sensor. For aviation use, I use an Oxiline, which uses the same sensor as the medical grade versions. If getting a bargain basement oximeter, I’d carry two in the plane so I could cross check. Especially if flying alone ar altitude.

https://oxiline.shop/product/oxiline-pulse/
 
Those Amazon pulse oximeters are fine for home use. The different brands all use the same sensor. For aviation use, I use an Oxiline, which uses the same sensor as the medical grade versions. If getting a bargain basement oximeter, I’d carry two in the plane so I could cross check. Especially if flying alone ar altitude.

https://oxiline.shop/product/oxiline-pulse/

Completely agree since most of the ones on Amazon are Chinese and I have found that <90% provide reliable results. Some considerable less. For Something I am using as a safety check needs better reliability than that.
 
I bought this one for home use. Always been close to readings at the doctors office. Haven't tried airborne, yet. Very happy with it. $25


Santamedical Generation 2 Fingertip Pulse Oximeter Oximetry Blood Oxygen Saturation Monitor with Batteries and Lanyard
 
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I have a $30-40 one that I picked up from an overseas vendor many moons ago, and it works great. However my Garmin Vivoactive 4 watch now has an SpO2 sensor and records and reports 24/7. I can pull up the number whenever I want to... Currently reading 92%.

I think I can set alarms for low values but I haven't looked into it as I don't generally fly that high.
 
I picked up a $30 unit on amazon, it worked great on the ground up to about 8K feet, then it was very intermittent beyond that. Returned it and picked up another one for around $40 off amazon, it read at all altitudes, but sometimes I needed to run the test 3 or 4 times to get a reading. Finally I was picking us meds at Rite Aid and they have a $60 Rite Aid branded one on the counter so I picked it up. Works GREAT, screen is easy to read even in direct sunlight (harder but readable) never fails a test and has zero issues so far.

Moral of the story, for me at least, don't skimp on a safety item like this.

YMMV
 
There was a research paper testing the accuracy of 6 different OTC oximeters. Conclusion was that 2 of them were accurate enough to meet the ISO standards:

RESULTS:

Pulse oximeter readings corresponding to 536 blood samples were analyzed. Four of the 6 oximeters tested showed large errors (up to −6.30% mean bias, precision 4.30%, 7.53 ARMS) in estimating saturation when Sao2 was reduced <80%, and half of the oximeters demonstrated large errors when estimating saturations between 80% and 90%. Two of the pulse oximeters tested (Contec CMS50DL and Beijing Choice C20) demonstrated ARMS of <3% at Sao2 between 70% and 100%, thereby meeting International Organization for Standardization (ISO) criteria for accuracy.

Both the Contec CMS50DL and Beijing Choice C20 are on Amazon, and are cheap enough you shouldn't be without one when flying.

My son and I, flying to Osh this year, at 7500MSL, I was at 83% and he was at 87% already. We went ahead and turned on the O2, why risk it? And, I feel way less fatigued after a long flight when using it, even way below the required 12.5.
 
Yes, I use oxygen from an Inogen G-5 that works great.
I have four of these little devices (all different manufactures) and none of them are worth the plastic they are made of. Can't read any of them in direct sunlight.
It said you could change the light emittance for readability, But still none of them work in a bright cockpit. Only if you shield them can you see the numbers.
If I was to buy another one I would want to try read it in the sunlight.
If you find one, Please let us know.
Thanks Art
 
Wellue o2 ring

Yes, I use oxygen from an Inogen G-5 that works great.
I have four of these little devices (all different manufactures) and none of them are worth the plastic they are made of. Can't read any of them in direct sunlight.
It said you could change the light emittance for readability, But still none of them work in a bright cockpit. Only if you shield them can you see the numbers.
If I was to buy another one I would want to try read it in the sunlight.
If you find one, Please let us know.
Thanks Art

I tried a bunch of the finger type and agree none are reliable. I was gifted a fancy Garmin Aviation watch with o2 sensor built in and it is finicky, requires your hand to be still, and need you to go to a specific screen to view the results. This was not satisfactory so I bought one of these Wellue rings and it works great. It vibrates if you drop below 85% and tracks/records the whole activity while you wear it as well as displays the results live. Highly recommend trying one. They are pricey but work exceedingly well.

https://getwellue.com/products/o2ring-wearable-pulse-oximeter
 
i’m a physician. i’ve found the Amazon oximeters to be sufficiently accurate, although as i said…i do carry a spare. i hadn’t heard about the Wellue thing however and i am intrigued.
 
Accuracy?

There's been some discussion on the absolute accuracy of various inexpensive pulse oximeters. IMHO, this misses the point. After all when in your normal life have you ever thought "Gee, I'm feeling a little tired, I feel like my oxygen saturation is 95% when I'm normally at 97%."

Instead of absolute accuracy, I hope that the pulse oximeter models that people are using are linear with respect to their true saturation level regardless of the actual number presented. Not being a physician, I really don't know (exactly) what the number my unit gives means, other than 100% is good. By the way, I've never seen anything higher than 96% on mine or lower than about 88%. So here's a test that I propose for those of us that don't know if their oximeters are accurate enough and working over a range of altitudes.

1. Check your level on the ground.
2. Fly up to 12,499 MSL and check your level again.

After this test, you will know if your meter works and you'll know the number that the FAA thinks is OK for you to fly without O2. This is just my .02, But be careful flaming me with all of the oxygen flowing through this thread. ;)
 
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Mostly off topic

2. Fly up to 12,499 MSL and check your level again.
;)

Here’s a trivia question I use on Flight Reviews, if I run out of things to say:
You’ve just reached exactly 12,501’ MSL. How long can you cruise there without supplemental oxygen?
A. 30 minutes
B. Forever
C. I need more information.(explain)
 
Instead of absolute accuracy, I hope that the pulse oximeter models that people are using are linear with respect to their true saturation level regardless of the actual number presented.
1. Check your level on the ground.
2. Fly up to 12,499 MSL and check your level again.

That is basically what the research article I linked to above did, but without using altitude to bring O2 levels down in the subject (they used some other apparatus to get stable O2 "plateaus"):

METHODS:

The accuracy of 6 low-cost finger pulse oximeters during stable arterial oxygen saturations (Sao2) between 70% and 100% was evaluated...Inspired oxygen, nitrogen, and carbon dioxide partial pressures were monitored and adjusted via a partial rebreathing circuit to achieve 10 to 12 stable target Sao2 plateaus between 70% and 100% and Paco2 values of 35 to 45 mm Hg...

The statement that stands out from the results should be this:
Four of the 6 oximeters tested showed large errors (up to −6.30% mean bias, precision 4.30%, 7.53 ARMS) in estimating saturation when Sao2 was reduced <80%, and half of the oximeters demonstrated large errors when estimating saturations between 80% and 90%
Meaning, they are not linear, and 4 out of 6 fell off in accuracy significantly where you needed it most, 70%-80% saturation levels, which is where cognitive decline really starts to get to you.

The 2 listed as being very accurate were accurate across that critical area, and would be the one I would buy, screen brightness/readability notwithstanding.

Totally agree though, anything above 90% on any of the meters means you are probably fine; on this last flight this weekend though, my wife was at 92% and was getting a headache. A couple of minutes on the O2, headache was gone, so some are more sensitive than others.

If you treat the cheaper/less accurate O2 meters as a binary, I think that would work fine too. As in, anything below 90%, we turn on the O2, don't really care about the particular number.

I was able to get myself set up with an O2 system for less than $200, and refills on a 20cf bottle is about $20, and lasts around 15-20 hours for 2 people at 10k feet.

If you aren't comfortable with DIY oxygen setup, the MH or Aerox are great setups too, and you have it turnkey. For me, it was kind of "I didn't know I wanted it until I had it, now I can't imagine going without it."

You’ve just reached exactly 12,501’ MSL. How long can you cruise there without supplemental oxygen?
A. 30 minutes
B. Forever
C. I need more information.(explain)

Unless this is a trick question, I think the answer is A legally, but you could bump down to 12,499 every 29 minutes and reset the clock :p

In reality though, I start seeing spots and feel a little breathless at 9k+. Your body actually responds more in correlation to DA than PA.
 
Even more off topic

Here’s a trivia question I use on Flight Reviews, if I run out of things to say:
You’ve just reached exactly 12,501’ MSL. How long can you cruise there without supplemental oxygen?
A. 30 minutes
B. Forever
C. I need more information.(explain)

Bob,

I cant imagine you running out of things to say!

KT
 
Unless this is a trick question, I think the answer is A legally, but you could bump down to 12,499 every 29 minutes and reset the clock :p
PA.

It is not a trick question; strictly speaking every pilot should know the answer.
Answer A is incorrect.
The FAA has previously issued their interpretation, that the 30 minutes is cumulative time on any given flight. You may not re-set the clock by flying lower, unless you terminate the flight (land).
 
The FAA has previously issued their interpretation

As a Reaganite, I trust you, but I’m gonna need some verification…

I have never heard that, and a quick search shows that’s it’s been debated forever about whether 91.211 actually means total exposure during “a flight” vs 30 minutes at a time. I can’t seem to find any official LOI about 91.211, and there’s a discussion about it in the AIM that seems to imply cumulative exposure above 12.5, like what you are saying, but then above 14k seems to imply per exposure event.

I agree though, it’s a great BFR question! Cause it will give both of us something to talk about, table-pound, talk past, personally interpret for hours :D

Anecdotally, my DPE on my CPL was happy with me reciting the reg and telling him I used an oximeter and used O2 way before the reg called for it, which is definitely the spirit of 91.211.

I heard from somewhere, no idea if it’s true, that the original idea was to set it lower than 12.5, but Rocky Mountain folks balked at this, since it would mean having to fly with O2 all the time.

I guess I want to change my answer to C then, I need more information: Who’s asking the question? :p
 
Well, above 14,000' it's "all the time", so there is little to debate whether it's cumulative or not. As to "above 12,500', the FAR says "..that part of the flight at those altitudes in excess of 30 minutes..." Since the FAA defines a 'flight' as 'chock to chock' time, it's hard for me to see any interpretation that flying below 12,500' during part of any one flight 're-sets' the clock.
Now as to O2 use:
The actual FAR says "...cabin pressure altitude...", e.g., the pressure altitude within the cabin (this covers pressurized aircraft). So you are supposed to set your altimeter to 29.92 (definition of "pressure altitude") and, if available, open the alternate static source within the cabin, to measure the 'cabin pressure altitude'. Note the FAR adds (MSL) which is extraneous, unless there's another definition of pressure altitude I don't know about. So for the example given, about half the time the answer is A, and about half the time the answer is B. It all depends on the altimeter setting in use, compared to 29.92".
BTW, this is also the technically correct answer. For a person at rest, the reduction of oxygen blood level is due to the limited rate of oxygen diffusion across the membranes in the lung, into the blood stream. This diffusion rate depends on pressure (actually partial O2 pressure). For a person at rest air density is not a factor. I've seen a few people suggest that density altitude should be used for deciding when supplemental O2 is needed, but that is incorrect.
 
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I used to have the best Oximeter and it would talk to you.
My 10 year old sons lips would start to turn blue about the time we were going through 7,500-8,000
Problem is he is now 40 years old and it doesn't work anymore.
Had to buy a regular unit.
Ha Ha Ha.
Art
 
However my Garmin Vivoactive 4 watch now has an SpO2 sensor and records and reports 24/7. I can pull up the number whenever I want to... Currently reading 92%..

For a healthy guy at sea level, 92% seems a bit low. Nobody breathing room air will read 100% because of physiological shunting but its usually not 92%. Are you a smoker?
 
Not sure if this data helps anyone or not, but I did collect this the first time going up with O2 installed, With a PIC on O2 as needed.

I took off and climbed to 13,500 ft, the total climb was done in just under 20 mins. Here are the O2 reading taken over the climb, taken as we crossed the altitude, and then taken again 5 mins after reaching 13.5K.

400 MSL before take off = 97%
@ 5K feet = 94%
@ 7.5K = 91%
@ 9.5K = 88%
@ 11.5K = 86%
@ 13.5K = 81%

After 5 mins at 13.5K without O2 I was at 71%, put on the O2 cannula and in 3 mins was back to 91% and a few mins later 98%.

Since then I have flown flights in the 9/10.5K range as usual and measured my O2 to find in some cases I was in the low 80% and even once in the mid 70's, so now I have O2 available at all times, adjusting flow as needed to keep us saturated in the 90's. I've noticed less fatigue after a few hours in the air vs. the same trips without the O2.

My 2 cents, YMMV
 
I have a $30-40 one that I picked up from an overseas vendor many moons ago, and it works great. However my Garmin Vivoactive 4 watch now has an SpO2 sensor and records and reports 24/7. I can pull up the number whenever I want to... Currently reading 92%.

I think I can set alarms for low values but I haven't looked into it as I don't generally fly that high.

I do trust that if my Apple Watch was to tell me that I am in atrial fibrillation, I probably am (I don’t have that cardiac issue). OTOH, that same watch has an oximeter function and I have not found it to be accurate at all…would never trust it as a consistently accurate indicator of my oxygen saturation for aviation use. IMHO, the absolute accuracy of an oximeter is more critical in the cockpit than it is in most medical use.
 
Perhaps we can help!

---- I am not trying to sell you guys anything, but rather share a bit of information you may or may not find useful. Obviously, I am not going to retire by selling O-2 meters, at any rate, I will share my findings in hopes it will benefit our group. When researching to find a meter that was affordable, available, and served the mission at hand I became a bit more educated on these tools. My Mandarin, and Chinese isn't up to par, so this was quite the undertaking. In dealing with several manufacturers and learning all I could I got lucky in finding one to work with us. We found, as stated a few times in this thread, they are not all equal or even close, and price is not a determining factor. We assume if you are looking for a meter here, you most likely are planning to use it in an airplane at altitude. As such its accuracy at altitude is a major concern, along with it being reliable, bright, self-turning off Etc. Most of these products are not intended to be used at altitudes above 10k, and the errors increase dramatically with more altitude. This I am sure is not what one would have in mind when seeking O-2 information. The units we offer do not suffer from this like most of the others, and the manufacturer states it in their accompanying literature. We hope this will help you should you be in the market for an O-2 meter. Thanks, Allan-:D-:D
 
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