Inogen

[Danb]

We’re all different in the way we breath and the saturation for each.eg using no oxygen at 8,000 ft I’m at 88% while Fran is still in the in the high 90’s near 99%. Therefore I need O2 at 8,000. As we increase altitude Fran is still above 90 % at 14,000ft. While on oxygen her saturation levels did not change much. We realized she is a mouth breather so she got little benefit from the oxygen, I decided to try her on the basic mask that came with the system and her levels obviously increased. Since her sat’s are much higher than mine I need to have my flow settings quite high while hers are set considerably lower. Thinking Don’s and Shirley’s levels are similar to each other while Fran’s and mine are dramatically different surprisingly I expected the opposite between us since she’s had a few heart attacks while my heart is ok.

The point being before reliance and assuming the settings of you and your passengers are in similar ranges may not be true we should early in the flight determine the oxygen needs of each. Assuming we’re in the range as given by the FAA for oxygen use shouldn’t be assumed.

I went to Oshkosh last week and brought a younger guy in very good shape and some 25 years younger I was alarmed when I tested his saturation at 8,000 it was around 87% this being tested with the three oxymeters I carry.

 

[EricJ]

25 minutes ago, Danb said:

I went to Oshkosh last week and brought a younger guy in very good shape and some 25 years younger I was alarmed when I tested his saturation at 8,000 it was around 87% this being tested with the three oxymeters I carry.

Was he impaired at all?   My sats run comparatively low with little to no impairment.   I outlasted everybody in my PROTE session and was still doing puzzles and answering questions at the end...I was impaired, but that was at the equivalent of 25000 ft.   Sats aren't really even comparable from person to person, so even if his sat looked low he may not have been impaired, or maybe he was, but the sat won't necessarily prove it one way or other at that level.

[Danb]

11 hours ago, EricJ said:

Was he impaired at all?   My sats run comparatively low with little to no impairment.   I outlasted everybody in my PROTE session and was still doing puzzles and answering questions at the end...I was impaired, but that was at the equivalent of 25000 ft.   Sats aren't really even comparable from person to person, so even if his sat looked low he may not have been impaired, or maybe he was, but the sat won't necessarily prove it one way or other at that level.

No although I thought he was going to fall to sleep I only did 11,000 and 12,000 due to his issue 

[Will.iam]

5 hours ago, Danb said:

No although I thought he was going to fall to sleep I only did 11,000 and 12,000 due to his issue 

Sleepiness is just one of many symptoms you can have of becoming hypoxic. That’s why you see most babies and small children that are crying on the ground in the cabin goto sleep once the cabin gets up to 8500ft. 

 

18 hours ago, Danb said:

We’re all different in the way we breath and the saturation for each.eg using no oxygen at 8,000 ft I’m at 88% while Fran is still in the in the high 90’s near 99%. Therefore I need O2 at 8,000. As we increase altitude Fran is still above 90 % at 14,000ft. While on oxygen her saturation levels did not change much. We realized she is a mouth breather so she got little benefit from the oxygen, I decided to try her on the basic mask that came with the system and her levels obviously increased. Since her sat’s are much higher than mine I need to have my flow settings quite high while hers are set considerably lower. Thinking Don’s and Shirley’s levels are similar to each other while Fran’s and mine are dramatically different surprisingly I expected the opposite between us since she’s had a few heart attacks while my heart is ok.

The point being before reliance and assuming the settings of you and your passengers are in similar ranges may not be true we should early in the flight determine the oxygen needs of each. Assuming we’re in the range as given by the FAA for oxygen use shouldn’t be assumed.

I went to Oshkosh last week and brought a younger guy in very good shape and some 25 years younger I was alarmed when I tested his saturation at 8,000 it was around 87% this being tested with the three oxymeters I carry.

 

Yes i have tested professional pilots that were below 87% at 8500ft and they didn’t feel anything was different or wrong and they were performing all their duties normally. They even think the device is not working properly until they put on an oxygen mask and it goes up to 99%. Again get your base line at sea level. You might be surprised to see you are not at even 95% on the ground! What worjs for one person could be lights out for another person at that level. Just like we note what the egt is at sea level and keep that number in the climb for best power. I keep what i read at 10,000 as my bare minimum for anything higher. 

[Scooter]

Agree with what’s right for one may not be right for another. During chamber rides you would notice some people effected faster then others and displayed different symptoms.

[Hank]

2 hours ago, Scooter said:

Agree with what’s right for one may not be right for another. During chamber rides you would notice some people effected faster then others and displayed different symptoms.

An important part of the altitude chamber experience is to notice and record your symptoms, so that you will have an opportunity to recognize and correct the issue if it happens, before falling into the happy hypoxic place.

[CCAS]

On 7/29/2025 at 3:15 PM, wingslevel said:

While running at a setting 5 or 6 I popped the breaker for the cigarette lighter (which is located back by the batteries on the Acclaim). Anybody else ever experience this? I replaced the 5 amp fuse with a 10 and fished a heavier gauge wire to the aft cigarette lighter. Now no more popped breakers.

While emailing back and forth with Jon at Pure Medical he advised the following:  "The amps while using without the battery are 3 amps, but if you charge the battery and use the unit, you will be using 10 amps."  Seems like a 10 amp CB (at least) is needed.  

[Aaviationist]

It’s not being a Karen when you are just stating facts. 
 

The experience of other in this thread show this unit has limitations, and you seem fine with operating WELL outside of those limitations both expressed by the manufacturer AND others in this thread. 
 

do what you want, just don’t crash into MY house. 

[N201MKTurbo]

I had a friend who went to Oshkosh with me in 13. On the first leg we were up high and on O2. I put the pulse ox on and it read mid 90s. I put it on him and it read 78. I was freaking out! I asked him how he felt. He said he felt fine He said “those things never work on me”. He said doctors an nurses always freak out whenever they use one on him.

[Hank]

55 minutes ago, N201MKTurbo said:

I had a friend who went to Oshkosh with me in 13. On the first leg we were up high and on O2. I put the pulse ox on and it read mid 90s. I put it on him and it read 78. I was freaking out! I asked him how he felt. He said he felt fine He said “those things never work on me”. He said doctors an nurses always freak out whenever they use one on him.

As we always said in the medical devices manufacturing community, "every body is different."

[Scooter]

I work on an ambulance and use a SPO2 monitor on all patients. I have and should notice a difference between the patients. A couple of readings I got were machine driven in that one minute it will read in the 80’s and the next it will read mid 90’s. Another factor that I have found is placement of the finger probe. Different finger’s different readings. In other words the finger is a reference.

[Pinecone]

On 7/30/2025 at 2:11 PM, Will.iam said:

What worjs for one person could be lights out for another person at that level. Just like we note what the egt is at sea level and keep that number in the climb for best power. I keep what i read at 10,000 as my bare minimum for anything higher. 

The rule of thumb I have heard is a minimum of 5% under your resting sats on the ground.

But you are very right about different people.  I have told this before, maybe even in this thread.   But one flight I had to go to 14,500 in a C-182 with two pilot friends to get over a ridge of clouds.  I was fine in the left seat.  I noticed the pilot flying from the right seat under the hood (CFII practice) started to have his head move around a good bit and he was not as sharp on heading and altitude.  I turned and looked and the other guy was out cold in the back.  We crossed the clouds and descended to 10,500 and both were fine.

[wingslevel]

On 7/31/2025 at 11:15 PM, CCAS said:

While emailing back and forth with Jon at Pure Medical he advised the following:  "The amps while using without the battery are 3 amps, but if you charge the battery and use the unit, you will be using 10 amps."  Seems like a 10 amp CB (at least) is needed.  

Very helpful. No real reason to charge the battery because it's only a backup and then i have my built-in tank as another backup.

Wondering if I just remove the battery altogether if it will work ok? ChatGPT says yes and that it will run cooler too. I will try that next.

[Pinecone]

14 hours ago, wingslevel said:

Wondering if I just remove the battery altogether if it will work ok? ChatGPT says yes and that it will run cooler too. I will try that next.

I run mine without the battery connected.

[wombat]

Before this thread is too old...

Let's talk about oxygen concentrators.   Do they introduce anything that could be hazardous as an aviator? 

 

The documentation I can find says they are not actually oxygen concentrators, they are nitrogen excluders, using zeolite to concentrate and exclude nitrogen.

This means the concentration of other elements is much higher than normal.  Below is a chart that shows this for 90% O2 and a 'perfect' concentrator that removes 100% of the nitrogen.

From reading https://pmc.ncbi.nlm.nih.gov/articles/PMC9646629/ they say that argon starts to be a problem at concentrations of 33%, so I think this is not a hazard.

I'm going to assume the other elements/molecules are equally nonhazardous at these increases in concentration.

I have not done any thinking about water yet but as a pure concentration of normal atmospheric elements, I don't think it's hazardous.

Gas concentrations with an oxygen concentrator:

	Normal Atmosphere	90% O2 concentration	"Perfect" oxygen concentrator
Nitrogen	78.07388%	5.75902%	0.00000%
Oxygen	20.94836%	90.03845%	95.54066%
Argon	0.93393%	4.01412%	4.25943%
Carbon dioxide[6]	0.04120%	0.17707%	0.18789%
Neon	0.00182%	0.00782%	0.00830%
Helium	0.00052%	0.00225%	0.00239%
Methane[7]	0.00018%	0.00077%	0.00082%
Krypton	0.00011%	0.00049%	0.00052%

 

[Hank]

8 minutes ago, wombat said:

I have not done any thinking about water yet but as a pure concentration of normal atmospheric elements, I don't think it's hazardous.

Too much water in your nose is definitely a bad thing . . .

[Will.iam]

Well for that matter too much oxygen is toxic too. Diving on nitrox or just oxygen at 42% limits you to 60ft as any deeper and you risk oxygen toxicity when induces convulsions which makes it extremely hard to keep a regulator in your month by then. 

[wombat]

Regarding the water, my concern is that over time atmospheric (dissolved) water might condense inside the tank and become liquid.  That liquid could then freeze when I'm at altitude.  Or it could experience deposition (frost) directly.  It could do that in one of the lines and block it.  It could do that in a valve, preventing it from operating correctly.   In either case, my oxygen is no longer usable even though a test on the ground might have demonstrated it working.  Or it could be working at altitude and then the build-up of ice increases and it just stops working as I'm flying along.

Some possible solutions:

If I am filling a portable tank, chill the tank (to condense the water), hold it upside down, and vent some oxygen.  If there is liquid water, that should drain it.  Although if the water concentration is just right, it won't ever be liquid.  Just like carb ice, it might just directly form frost where the pressure gets low at the valve or in the line after the valve.

For the permanently mounted tank... Umm....  I don't know how to get water out of that.   Better to not get any in, but I'm not sure how to go about that.   

[Scooter]

Oxygen is a dry gas. If you are using aviation oxygen there should not be any water involved. That is one of the reasons that during long transports or continuous use of oxygen they incorporate water downstream to moisturize it. It is also one of the reasons for the tank checks every five years. It checks for rust and moisture in the tank. As you’re coming down from altitude the heat inversion should melt any ice that is in the system.

Edited Sunday at 02:32 AM by Scooter
Spelling

[Aaviationist]

Today I tested a G5 at 10500 and up compared with my o2d2 and tank. 
 

First, I used 3 different brands of pulse ox and alternated between them. One had official approval the others did not. 
 

on the ground the medical grade unit showed me at 94%. This was the case on every finger but my thumb. 
 

the Amazon units varied widely depending on finger. Index finger was the closest at 97% while ring finger showed 73%. About the same between the two. based on this I did not use the Amazon units for the flying test. 
 

at 10500 on the G5 I was 94%. This was solo use. On the o2d2 I was 96%
 

at 12500 on the G5 I was 93%. On the o2d2 I was 96%
 

at 15500 on the G5 I was 91%. On the o2d2 I was 95%
 

at 17500 on the G5 I was 88-89%. On the o2d2 I was 94. 
 

it would seem the G5 works as described in the documentation, and does not do exactly ehat the manufacturer says it does not do. 
 

personally, I would not feel comfortable single pilot with a G5 as my o2 source above 12k. I would absolutely never use this above 12k with 2 people. 
 

personally I would not use a pulse ox not medical grade. The widely available units are wildly inaccurate when not placed perfectly on a perfectly still finger. The more expensive medical grade units appear to have better filtering and reliable measurements. 
 

all of this data is recorded and I will compile and graph it later. 

Edited Monday at 03:33 AM by Aaviationist

[NickG]

48 minutes ago, Aaviationist said:

Today I tested a G5 at 10500 and up compared with my o2d2 and tank. 
 

First, I used 3 different brands of pulse ox and alternated between them. One had official approval the others did not. 
 

on the ground the medical grade unit showed me at 94%. This was the case on every finger but my thumb. 
 

the Amazon units varied widely depending on finger. Index finger was the closest at 97% while ring finger showed 73%. About the same between the two. based on this I did not use the Amazon units for the flying test. 
 

at 10500 on the G5 I was 94%. This was solo use. On the o2d2 I was 96%
 

at 12500 on the G5 I was 93%. On the o2d2 I was 96%
 

at 15500 on the G5 I was 91%. On the o2d2 I was 95%
 

at 17500 on the G5 I was 88-89%. On the o2d2 I was 94. 
 

it would seem the G5 works as described in the documentation, and does not do exactly ehat the manufacturer says it does not do. 
 

personally, I would not feel comfortable single pilot with a G5 as my o2 source above 12k. I would absolutely never use this above 12k with 2 people. 
 

personally I would not use a pulse ox not medical grade. The widely available units are wildly inaccurate when not placed perfectly on a perfectly still finger. The more expensive medical grade units appear to have better filtering and reliable measurements. 
 

all of this data is recorded and I will compile and graph it later. 

What is the brand of the medical grade Pulse Ox that you used?

[1980Mooney]

51 minutes ago, Aaviationist said:

Today I tested a G5 at 10500 and up compared with my o2d2 and tank.

at 10500 on the G5 I was 94%. This was solo use. On the o2d2 I was 96%

at 12500 on the G5 I was 93%. On the o2d2 I was 96%

at 15500 on the G5 I was 91%. On the o2d2 I was 95%

at 17500 on the G5 I was 88-89%. On the o2d2 I was 94. 

Was the Inogen G5 set to flow rate #6 (highest) during all test altitudes?

[Aaviationist]

6 hours ago, 1980Mooney said:

Was the Inogen G5 set to flow rate #6 (highest) during all test altitudes?

Yes. It was turned all the way up to its max output for the full duration. 
 

The Nonin TruO2 was the pulse ox.