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# How much helium do one need to lift 1Kg

05/07/2008 10:36 AM

Hi All

I was wondering how much helium is needed to make 1km weight natural boiancy or give some lift

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#1

### Re: How much helium do one need to lift 1Kg

05/07/2008 10:54 AM

Umm, seriously? It takes 1kg of helium to counter the gravity from a 1kg weight. Sheesh.

Now for real fun, with the advent of an R&D complex in India and China, the consumption of helium for supercooled experimental work has greatly increased. To complicate things we are all running out of the "easy" natural deposits; and since helium has a nasty tendency to escape our atmosphere because it is so light, I would really recommend people stop lifting weights via helium for the sake of lifting weights.

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#5

### Re: How much helium do one need to lift 1Kg

05/08/2008 3:24 AM

Hello Ben Bonsens,

Not sure where you got your info but it is wrong.

Excluding the weight of the air it displaces 666 grams of helium will lift a 1 kg load. To be safe near enough 700gm.............. ~700gm (as I understand it). Because the lift ratio is roughly 2-1 (two to one).

Knowing that 4 grams of helium occupies that same volume as 28.5 grams of
air, we can see that four grams of helium will lift up to six grams:

And, I do not mean to be rude but most of your post was 'off topic'. Sorry to be so pedantic.

jfmfit

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#16

### Re: How much helium do one need to lift 1Kg

05/08/2008 12:25 PM

I humbly am eating crow at the moment.

Thanks for correcting me though, its the only way we learn.

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#17

### Re: How much helium do one need to lift 1Kg

05/08/2008 1:50 PM

Even if the correction is nearly as far in error as you were yourself?

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#20

### Re: How much helium do one need to lift 1Kg

05/08/2008 3:21 PM

Hello Ben Bonsens,

I too am eating crow as my answer copied and pasted directly from another sight was as wrong if not 'more wronger' than yours! As it turns out the answer is 166grams of helium. I do not pretend to grasp it all.................I will just blame it all on my epilepsy. The thing is I can't think straight to because of a fit earlier, so pasted what appeared to be a correct reply. There was at least one other person who came up with the same answer by visiting the same site I did!

Live and learn eh?

jfmfit

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#21

### Re: How much helium do one need to lift 1Kg

05/08/2008 4:19 PM

In my distorted world view, being wrong is a necessary first step towards understanding. Around the lab I repeat the mantra, "For Science!", and proceed with something in the vain hope that I'm going to learn something at the end. Somedays I learn something. Somedays I don't. Today was a good day.

Certavi et vici.

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#24

### Re: How much helium do one need to lift 1Kg

05/08/2008 5:12 PM

You try to succeed, Or, you have tried and have succeeded?

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#29

### Re: How much helium do one need to lift 1Kg

05/08/2008 6:18 PM

"I have fought and conquered." Family motto

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#30

### Re: How much helium do one need to lift 1Kg

05/08/2008 7:24 PM

OK. I am interested in Family Motto's. Unless I have inadvertently already posted my surname I won't mention it here but, I have a really rare name and I will try to find the Motto that goes with it. I did have it but after a computer crash I lost everything several years ago, and on a different computer. I will try to get it though and then write directly to you.

Thanks for getting back to me.

jfmfit (John)

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#33

### Re: How much helium do one need to lift 1Kg

02/25/2009 7:53 PM

that wrong, you only need around 0.182 grams to lift 1kg.

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#34

### Re: How much helium do one need to lift 1Kg

02/26/2009 8:04 AM

The two contributions rated as GAs got this about right, so presumably you mean 0.162-kg (or 162-gm), which is the theoretical limit at sea level*? Of course, in practice the envelope is under tension, which in isolation would increase the amount needed. Then, we have to account for the weight of the envelope etc. That would be all we would need to consider for a small experimental set-up - and for this case practical checks would indicate the envelope about halved the available load (there may be a small error in that experiment due to moisture).
Larger systems are generally more efficient - but there is little purpose if they cannot rise to greater heights where the effects of the tension in the envelope is greater and the relative density of the air is somewhat lower - perhaps we should expect a practical value of about 250-gm of helium for 1-kg of lifted load.

*But what is a few orders of magnitude between friends?

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#35

### Re: How much helium do one need to lift 1Kg

12/24/2016 3:30 AM

how you are prooving that 0.182 grams are sufficient to lift 1 kg?

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#2

### Re: How much helium do one need to lift 1Kg

05/07/2008 1:30 PM

You need about 700g of helium to generate 1kg lift (assuming the helium is at the same temperature and pressure as the surrounding air). See here.

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#3

### Re: How much helium do one need to lift 1Kg

05/07/2008 11:26 PM

About one cubic meter per kg of lift (assuming standard temp and press.)

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#4

### Re: How much helium do one need to lift 1Kg

05/08/2008 3:07 AM

Hello,

I did know this and had forgoten so I went back to the site I first saw it. And this gives a precise answer. I have pasted the article for you to read below.

## Helium Lift Power

So, to lift 1000 grams (1 kg), you need 666 grams (~0.7 kg) of helium:

name Paul status other age 30s Question - I would like to know the lifting power of Helium eg: How much helium to lift 1kg Any information would we great. ------------------------------------------------ That depends on the density of air and the density of the helium. For simplicity's sake, let's say the air and the helium are at the same temperature and pressure. In that case, four grams of helium will occupy about the same volume as 28.5 gm/mole of air. To lift an object, you need for the mass of the object + the mass of the helium to be less than the mass of the air it displaces. Since any object you want to lift will probably have a much greater density than air or helium, let's neglect its volume for simplicity's sake (in other words, we'll neglect the mass of the air displaced by the object, because it will probably be only a small part of the mass of the air displaced by the helium and the object together). Then we can say that you need the mass of the object + helium to be less than the mass of the air displaced by the helium. M + Mh < Ma, where M is the mass of the object, Mh is the mass of the helium, and Ma is the mass of the air displaced. Our shortcut of neglecting the volume of the object just says that Ma = (28.5/4)Mh, that is, a given mass of of helium will displace (28.5/4) times its mass of air. Knowing that 4 grams of helium occupies that same volume as 28.5 grams of air, we can see that four grams of helium will lift up to six grams: M + Mh < Ma M + Mh < (28.5/4)Mh M < (28.5/4)Mh - Mh M < Mh [(28.5/4) - 1] M < Mh (6.1/4) M < 4g (6.1/4) M < 6.1g. So, to lift 1000 grams (1 kg), you need 666 grams (~0.7 kg) of helium: M < Mh (6.1/4) 1000g < Mh (6.1/4) (4/6.1) 1000g < Mh Mh > ~666g. How much volume of helium is this? It depends on the temperature and pressure. Neglecting the volume of the object to be lifted becomes a more serious error as it becomes a larger fraction of the total volume. Under normal conditions (ambient temperature and pressure), this is a small error. Richard Barrans Jr., Ph.D. =========================================================jfmfit

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#6

### Re: How much helium do one need to lift 1Kg

05/08/2008 3:56 AM

I don't understand this at all:

Air weighs about 1.2 Kg per cubic meter. Helium weighs less than 0.2 Kg per cubic meter so, Ken's answer 1 cubic meter (~0.17 Kg) per Kg must be right.

I've ignored the weight of the balloon material which must be significant, but can be easily weighed along with the payload.

What on earth does this mean?

Knowing that 4 grams of helium occupies that same volume as 28.5 grams of air, we can see that four grams of helium will lift up to six grams.

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#7

### Re: How much helium do one need to lift 1Kg

05/08/2008 4:57 AM

Hello Randall,

I may well not explain this correctly so wish me luck.

4grams of helium will lift 6grams of load, including the air it displaces, But of course the helium will take up a lot more space. You could be confused by the mention of weight and then volume? Just a try to explain as best I can, bearing in mind this is the first time I have looked at this equation.

hope this helps...........

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#9

### Re: How much helium do one need to lift 1Kg

05/08/2008 7:18 AM

I too have no idea what these explanations (posts 4 and 7) can possibly mean.

The easiest way to look at this problem is that the helium doesn't lift anything - it is the air that the helium displaces that does the lifting. And the air has to lift the helium (and the envelope) as well as the nominal load.

So, 4-gm of helium will displace about 28.5-gm of air. As a result, the combination will lift about 24.5-gm of load** (the load must include the envelope and all other encumbrances). Translated, that means that about 1-gm of helium fill is required for each 6.2-gm (approximately) of load. This multiplier depends only on the composition of the air - not on its temperature or density, so it will still be relevant at 1-km (as the atmosphere is mostly nitrogen up to quite high altitudes).
In case the questioner meant how much He fill would be required to raise 1-kg, the answer is about 160-gm.

N.B. Tension in the envelope means that the pressure of the helium will be slightly greater than the air it displaces; however, most practical envelopes are designed so the pressure differential remains small up to the maximum intended working height. Nevertheless, I would recommend allowing for at least a 10% margin, with the actual fill determined empirically.

**Maybe your original article meant 6gm of load for each gm of helium, but this got corrupted in the editing??

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#10

### Re: How much helium do one need to lift 1Kg

05/08/2008 7:47 AM

Hello Physicist?,

I have tried to understand it too and also tried to explain it. I actually got the info from the same site as cms engineer. I pasted the entire article and if you have time to read it, the whole thing makes sense.

I notice there is a huge difference between your answer and the one I an cs engineer gave of ~700grams. That is unless I have missed something in your post? I may have done. Can you explain the difference in the answers for me please? As I believe your answer was 160 grams. I have checked two sites and they both come to roughly the same conclusion. This includes the helium balloon site.

jfmfit

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#12

### Re: How much helium do one need to lift 1Kg

05/08/2008 9:11 AM

I pasted the entire article and if you have time to read it, the whole thing makes sense.

No it does not. Parts of it make sense, but when it gets to the point of actually formulating the math, it turns to gibberish:

Knowing that 4 grams of helium occupies that same volume as 28.5 grams of air, we can see that four grams of helium will lift up to six grams:

Who knows what the thoughts of this writer might have been, but certainly that statement makes no sense. You could assume that "four grams" was a typo and that "one gram" was intended, but then the calculations use the incorrect ratio to come up with an answer that is off by a factor of four. Sheeesh.

I'm trying to think of a PhD program that does not require a grasp of at least 4th grade arithmetic.

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#13

### Re: How much helium do one need to lift 1Kg

05/08/2008 9:30 AM

At the risk of sounding rude, Fyz already explained it. Just read through his quite clear explanation. The article you provided is simply wrong because the profoundly simple math is obviously wrong. In the reality most of us appear to share, 1 is not equal to 4.

You are relatively new to CR4, but you will find that Fyz's ratio of "good answers" to total posts is completely misleading. As far as I have seen, all of his answers are good answers.

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#15

### Re: How much helium do one need to lift 1Kg

05/08/2008 10:00 AM

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#18

### Re: How much helium do one need to lift 1Kg

05/08/2008 2:23 PM

in my attempt at explaining I was trying to make the figures I found fit.

On this how much helium to lift 1 kg, I went to the driskillsguide a little while ago and I think you Blink, went to the same site? And it states:

1 cubic metre of helium will lift 995.87 grams, and,

the weight of a cubic metre of helium is indeed, 166.24 grams.

Looks like I am kissing *ss again!

My first post was copied directly, and it appears it is way off the mark.

I am sorry for any misleading ideas which may have come from my 'expert' post. That goes to the physicist? and to you Blink.

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#23

### Re: How much helium do one need to lift 1Kg

05/08/2008 5:01 PM

No need to apologize at all, particularly to me. It certainly looks like you were trying to be helpful. However, I'd have to say your response to Randall came across as a little arrogant to me: you were saying that he was "confused" whereas he was not confused at all. So if any apology is due it might be to him.

Ironically, the phrase (from the good Doctor Barrans) you quoted in your correction to Randall happens to be completely wrong, and so wrong that it is nonsensical. (Out of all the phrases you might have picked, you picked the one that is not only true nonsense, but that stands out as nonsense even if you know nothing about buoyancy, helium, or air.) It seems to be the core problem with Barrans's lengthy and tedious analysis.

Interesting that Dr Barrans only got three sentences into his explanation, when he started going stupid on us: In that case, four grams of helium will occupy about the same volume as 28.5 gm/mole of air. (He probably intended to write "... 28.5 grams of air") My advice would be to read through things you snatch from the web before posting them. If what the original article says is nonsensical, then your repeating it can make you look a bit nonsensical as well.

So no apology is necessary, your posts are their own punishment. (For which I will apologize, if you take it as anything other than a well-intentioned jest. Your posts are always welcome here.)

Fyz's answer points out that it is really misleading to say that some quantity of helium lifts some amount of weight. The thing doing the lifting is air. Along similar lines, one would ordinarily not say "how much air is required to lift a boat on the water". The buoyancy is provided by the water, not the air. Filling a sealed boat with helium instead of air would scarcely change how it floats on its lines (although it might be disconcerting for any occupants).

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#28

### Re: How much helium do one need to lift 1Kg

05/08/2008 5:34 PM

I feel bad because it was such a stupid mistake and, after making a mistake in an answer a few days ago! I should have checked out a site which gave the Molecular weight of He. It would have been simple to work out the answer then. I did go to the site that I think you went to that gives volumes and weights that are needed to lift a particular amount. Sorry I cannot recall the site as I type now but, it was a really interesting site, which I have copied a short-cut from.

I did read but did not absorb! I take heed of your gentle tap of my wrist.

You never know, I may get something correct one day? LOL!

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#14

### Re: How much helium do one need to lift 1Kg

05/08/2008 9:59 AM

I've found the mistake in your posting.
As Blink implies, it is so elementary I wouldn't have thought to look for it. I have written the correct equations (emboldened) on the left, with the original (incorrect) lines retained on the right.

M + Mh Ma
M + Mh (28.5/4)Mh
M (28.5/4)Mh - Mh
M Mh [(28.5/4) - 1]
M Mh.[24.5/4] . . . . . . . . . . . . M < Mh (6.1/4)
M ≤ 6.1.Mh . . . . . . . . . . . . . . . . . M < 4g (6.1/4)

So, if you remove the mistake, you will see that your entry should predict that one gramme of Helium would raise 6.1-gm of load.

BTW, in case you missed it: if you convert this (or my data) {both of which are given in terms of the mass of Helium} to volumes at standard temperature and pressure, you will arrive at Blink's "quickly-given" approximation of 1-cu.m/kg of lift.

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#19

### Re: How much helium do one need to lift 1Kg

05/08/2008 3:02 PM

Hello Physicist?,

I have appologised for my mistake to both you and ken.

(In fear of asking a stupid question), do you think the confusion could have been make by mixing the 'mole' weight and the grams up? Does a Mole of helium weigh 4 grams? As stated by guest at 12:56.

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#22

### Re: How much helium do one need to lift 1Kg

05/08/2008 4:39 PM

Hello jfmfit

No need to apologise - we learn by making mistakes, and this is as good a place as any to make them**. There are many reasons I believe this. A first is that all readers are expected to make up their own minds, so mistakes are not likely to cause harm. A second is that there are enough people here who will take up "revision" problems, so a (more-or-less) correct answer usually emerges. A third is that, if you never make a mistake you are probably wasting your life doing things that are too easy.

BTW, my comment on the level of error was not directed to you as an individual CR4 contributor, but at the originating site, which I looked at following Blink's comment. That site purports to be written by people who are qualified in the specific areas - and also subject to checks and revisions - all clearly inadequate in this case.

Regarding the error: either the mistake was due to simple slapdash writing of equations***, or it was of a type that is outside of my working range. [Even if it was the former, basic knowledge of the relative densities should have been more than sufficient for anyone with insight into the physics to have noticed there was an error and corrected it]. I'm afraid I can't shed further light on the matter.

Regards

Fyz

**provided one is big enough to admit it to one's-self, which you have demonstrated you are
***which I do all the time - which is why I need to redo most things without looking at the original version - and for serious work the workings would be separated by a few days)

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#25

### Re: How much helium do one need to lift 1Kg

05/08/2008 5:17 PM

You are a kind man fyz!

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#27

### Re: How much helium do one need to lift 1Kg

05/08/2008 5:25 PM

I only try to be fair. That is not at all the same thing (as my colleagues would tell you, after they had told you I often don't succeed at the fairness).

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#26

### Re: How much helium do one need to lift 1Kg

05/08/2008 5:22 PM

Hello Randall,

I want to offer you my apologies for inferring you were confused.

It turns out I was more than confused myself! I WAS WRONG! I do have mental problems, namely, I am stupid!

However I did copy and paste directly from a site that was supposed to be written by 'experts'. They clearly are not.

Take care....................

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#31

### Re: How much helium do one need to lift 1Kg

05/09/2008 3:30 AM

No problem John,

All,

I have written to Ask an idiot a scientist thus:-

------------------------------------SNIP-----------------------------------------

To: 'sysop@newton.dep.anl.gov'

With reference to the following post:-

http://cr4.globalspec.com/comment/223072/Re-How-much-helium-do-one-need-to-lift-1Kg

Randall

-----Original Message-----

Sent: Thursday, May 08, 2008 11:42 PM

To: Randall

write to sysop@newton.dep.anl.gov

-----Original Message-----

From: Randall

Sent: Thu 5/8/2008 8:33 AM

Name: Randall

Status: other

Location: WY

Email: Randall.Bell@BT.com

http://www.newton.dep.anl.gov/askasci/phy99/phy99471.htm Is frankly rubbish, but, I have seen it copied on other sites. How do I get to correct it?

------------------------------------SNIP-----------------------------------------

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#32

### Re: How much helium do one need to lift 1Kg

05/09/2008 11:17 PM

Hello Randall,

isn't the Newton site a private one? Well, as much private as you can get on the www? I am not thinking to clear after a fit earlier Randall. Have you actually sent an email to the owner of the site? I am sorry I just can't think of the proper name for the person in charge of any site on the www. That site puts itself forward as the epitome of excellence, when it patently is not!

Certainly made a fool out of me and is it gsm engineer?

Take care Randall and let me know the outcome. If they are truly scientists, they should own up and swallow their pride and remedy the mistake. If a person reallied on that site only as they were building a lighter than air model, it could end up in a very sorry mess?

Take care, jfmfit (John)

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#8

### Re: How much helium do one need to lift 1Kg

05/08/2008 5:34 AM

Joined yet?

Did you realise your question does not make sense?

To quote:.......................to make 1Km weigh natural buoyancy or give some lift.

I think you should have said 1Kg?

just a thought. Did anyone else notice this sloppy mistake?

jfmfit

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#11

### Re: How much helium do one need to lift 1Kg

05/08/2008 7:56 AM

A mole of helium weighs 4 grams. A mole of air weighs 28.5 grams. A mole of any gas occupies the same volume. So the bouyancy is the difference, 24.5 grams per mole of helium. Therefore 4 grams produces 24.5 grams of "lift" in air. So the answer is about 1/6 kg of helium will lift 1 Kg.

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