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How to measure Long volume

Thread Status: Hello , There was no answer in this thread for more than 60 days.
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New Member
Sep 4, 2001
Is there a way to measure your longvolume at home?
With simple tools I mean?
Not accurately :t

I used to try it with a big deep bucket, a bit of tubing and a large enough cannister (10 litres would be top).

1) graduate your cannister by filling it up with water, 0.25 litres at a time. graduate the entire perimeter.
2) fill the bucket/bath
3) Submerge the cannister so it is full of water. place the tube in the aperture, and hold it upside down in the water.
4) Blow into the pipe!
5) let the cannister rise out of the water - but make sure it is level (graduations)

My god, that takes me back years back to my days of :head

It even makes me think about having another go! :king
Sounds like a nice experiment for a rainy weekend.
10 liter bucket should be big enough I reckon
That ofcourse will give you lung volume without residual volume, wich varies from person to person, but should be somewhere around 20%-25% of total lung volume.

Good luck.
aloha jvoets
If you have access to a pool, see how much air you can make sink when you empty your lungs (a four litre container should be big enough). Then see how much lead it takes to make you sink with full lungs. A little math and you have Vc. Add 24% and you have Vt.
You can also exhale into an empty nylon bag and fit it tightly into a measured container - flatten it with a cardboard, and try not to pressure it. Isn't it the simplest?
Bill's idea is OK - but because you will submerge yourself, you will get a certain amount of blood shift. So it won't give the same result as on land unless you do it damn quick!

The 'stick it in a bag' approach is a great one - very simple but can be hard to measure well.
Oh - and the 24% isn't fair - Residual capacity is very variable between individuals. I have a model that shows how residual capacity affects deep diving ability with normal ear clearing techniques....
Ben Gowland:
The 'stick it in a bag' approach is a great one - very simple but can be hard to measure well.

Hard to measure? just take a round container (a bucket for the monsieur!), graduatly fill it with water and mark the amounts.
Empty the container.
Take a large empty garbage bag, exhale into it. tie the end (leave plenty of room in the beg so it'll get the shape of the container when pressed gently with a flat object (a piece of cardbaord).
and you have measured your vital capacity.
Oh - and the 24% isn't fair - Residual capacity is very variable between individuals. I have a model that shows how residual capacity affects deep diving ability with normal ear clearing techniques....
Well, you can only estimate the residual volume, but 4% error won't make such a big difference.

But I'de really like to see that model, since I think I need to work on my residual volume.

P.S:If an exact result is important, you would'nt be checking you lung volume at home. :D
For exact results, just ask the doctor to send you to a spirometer test (on the account of asthma or something).


When you come to dive this weekend (in the Netherlands), I'll bring my spirometer so we can measure your lungvolume... :D

Ciao, Jorg Jansen
AIDA Nederland
Hey Ben
We're measuring the air. Would it care what the blood does? Maybe if it leaks out of the body but, even then it's so close to water....
Sorry Bill - I don't think I explained myself clearly.

A blood shift volume will dramatically change the reisdual volume in the lungs - so it does make difference, although, having given it more thought, I think your method could be very useful for trying to get a handle on how much blood shift one can get.

Dare I say it........fart volume!

I.e. other gases in the alimentary canal - I suppose as long as you don't fart during your measurements - it shouldn't make much difference.

Do you guys use the word fart - what is the common equivalent.

As I am sure you are aware there are A LOT of euphemisms for it in Britain....
Swallowing air at depth

Has anyone heard of or experienced swallowing air at several atmospheres? I would think this could be extremely dangerous, especially if a lungfull of air could be swallowed in a mouthful. Imagine that ascent! With all of the posts and attmepts to manipulate the glotis, epiglotis, etc., in attempts to find a better way to equalize, I find it hard to imagine no one accidentally swallowed air. What if one couldn't burp fast enough on ascent?

I think it happned once to my scuba partner, cause when we returned to the boat he burped quite alot. But in scuba the ascend is slow enough to prevent any trouble.

I just don't think that in Freediving it would be that easy to swallow WHOLE of your lung's volume, only a small portion by accident, and that, might only make you burp. :)
thinking again....look out

Happens all the time to me if I have trouble clearing at depth and use a lot of force, a few burps on the surface is all that I needed.....or it comes out the other end tomorrow.
I think you've solved a riddle for me. My first reaction was 'For Pete's sake, how much shift can you get on the surface and if it chases the air into the lungs, it has no affect on the measurement.' Then a little lite came on. On my third dive I do a 'neutral depth' check. If I check again later, it is a shallower depth. Could blood shift be reducing my total lung volume by almost 10%, on the surface? How long does it take blood to un-shift?
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