Measuring rucksack volume ?

Rob G

Has anyone a bright suggestion for measuring the volume of the several
older rucksacks I have in the house.

The reason is that I want a new lightweight one for 2 to 3 day trips
and I really don't know what 'manufacturer's' volume I want, but if I
load up one the sacks I have and can get some sort of measurement,
then I've got a starting point.

Thanks

Rob

Dominic Sexton

In article
<bfb7a464-6182-43d5-9797-d0361f54c1fc@n20g2000hsh.googlegroups.com>, Rob
G <robkgraham@btinternet.com> writes
>Has anyone a bright suggestion for measuring the volume of the several
>older rucksacks I have in the house.
>
>The reason is that I want a new lightweight one for 2 to 3 day trips
>and I really don't know what 'manufacturer's' volume I want, but if I
>load up one the sacks I have and can get some sort of measurement,
>then I've got a starting point.

Well if they are big name sacks some folk here might actually know so
you might want to post the make / model if you have it.

Other than that if they are a simple main compartment (not tapered and
no big pockets) you can work out the cross sectional area and multiply
it by the height. That should get you a good estimate.

--

Dominic Sexton

Peter Clinch

Dominic Sexton wrote:

> Other than that if they are a simple main compartment (not tapered and
> no big pockets) you can work out the cross sectional area and multiply
> it by the height. That should get you a good estimate.

To refine it see if you can find some packing chips (those foam 's'
thingies to keep stuff from getting trashed in transit) and a large
square section box. Fill up the pack, and then pour it into the box,
and measure the volume in the box (this is similar to the "official"
method several manufacturers use, though they use dried beans because
they flow better and don't compress: you could use dried beans too, but
you'll need quite a lot and large quantities tend to be harder to come
by than packing chips).

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net p.j.clinch@dundee.ac.uk http://www.dundee.ac.uk/~pjclinch/

Rob G

On 5 Dec, 08:30, Peter Clinch <p.j.cli...@dundee.ac.uk> wrote:
> Dominic Sexton wrote:
> > Other than that if they are a simple main compartment (not tapered and
> > no big pockets) you can work out the cross sectional area and multiply
> > it by the height. That should get you a good estimate.
>
> To refine it see if you can find some packing chips (those foam 's'
> thingies to keep stuff from getting trashed in transit) and a large
> square section box. Fill up the pack, and then pour it into the box,
> and measure the volume in the box (this is similar to the "official"
> method several manufacturers use, though they use dried beans because
> they flow better and don't compress: you could use dried beans too, but
> you'll need quite a lot and large quantities tend to be harder to come
> by than packing chips).
>
> Pete.
> --
> Peter Clinch Medical Physics IT Officer
> Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
> Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
> net p.j.cli...@dundee.ac.uk http://www.dundee.ac.uk/~pjclinch/

Good logic, Pete. Just wondering what I've got that I could do that
with. I was wondering about a large poly bag and the water tap, but I
can see all sorts of things going wrong with that !!

A large bag of gravel from one of the sheds might be the cheapest and
most re-useable option. You've set me thinking anyway, thanks

Rob

Rob

dont@even.ask

On Wed, 5 Dec 2007 00:50:45 -0800 (PST), Rob G
<robkgraham@btinternet.com> wrote:

>
>Good logic, Pete. Just wondering what I've got that I could do that
>with. I was wondering about a large poly bag and the water tap, but I
>can see all sorts of things going wrong with that !!

That was my first thought.

1) Put bathroom scales in bath
2) Put ruckack liner in rucksack
3) Put rucksack on scales and weight it
4) Fill liner with water
5) Note weight on scales
6) Calculate volume from weight difference
7) Upend rucksack extracting scales and sack a.s.a.p.

Now what could possibly go wrong? ;-)

John D.

Peter Clinch

dont@even.ask wrote:

> 1) Put bathroom scales in bath
> 2) Put ruckack liner in rucksack
> 3) Put rucksack on scales and weight it
> 4) Fill liner with water
> 5) Note weight on scales
> 6) Calculate volume from weight difference
> 7) Upend rucksack extracting scales and sack a.s.a.p.
>
> Now what could possibly go wrong? ;-)

Problem is if the water gets out it'll go everywhere as it's too runny,
but if you were to use something a little thicker, like, say, tomato
ketchup... ;-)

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net p.j.clinch@dundee.ac.uk http://www.dundee.ac.uk/~pjclinch/

John Dawson

On Wed, 05 Dec 2007 16:40:55 +0000, Peter Clinch
<p.j.clinch@dundee.ac.uk> wrote:

>dont@even.ask wrote:
>
>> 1) Put bathroom scales in bath
>> 2) Put ruckack liner in rucksack
>> 3) Put rucksack on scales and weight it
>> 4) Fill liner with water
>> 5) Note weight on scales
>> 6) Calculate volume from weight difference
>> 7) Upend rucksack extracting scales and sack a.s.a.p.
>>
>> Now what could possibly go wrong? ;-)
>
>Problem is if the water gets out it'll go everywhere as it's too runny,
>but if you were to use something a little thicker, like, say, tomato
>ketchup... ;-)

On second thoughts perhaps water-filled condoms would be better. You
could fill up any side pockets with them too.

John D.
--
John Dawson at home in Kendal, Cumbria.
Lake District Walks Web Pages http://www.lakedistrictwalks.com/
Kilimanjaro trip at http://www.lakedistrictwalks.com/kilimanjaro/
Egypt trip at http://www.lakedistrictwalks.com/egypt/

PeterC

On Wed, 05 Dec 2007 16:40:55 +0000, Peter Clinch wrote:

> dont@even.ask wrote:
>
>> 1) Put bathroom scales in bath
>> 2) Put ruckack liner in rucksack
>> 3) Put rucksack on scales and weight it
>> 4) Fill liner with water
>> 5) Note weight on scales
>> 6) Calculate volume from weight difference
>> 7) Upend rucksack extracting scales and sack a.s.a.p.
>>
>> Now what could possibly go wrong? ;-)
>
> Problem is if the water gets out it'll go everywhere as it's too runny,
> but if you were to use something a little thicker, like, say, tomato
> ketchup... ;-)
>
> Pete.

Make sure the bath's clean, use beer (or whatever you like), then a leak's
an opportunity, not a problem[1].

[1] ensure plug is in.
--
Peter.
You don't understand Newton's Third Law of Motion?
It's not rocket science, you know.

Rob G

On 5 Dec, 18:12, PeterC <giraffenos....@homecall.co.uk> wrote:
> On Wed, 05 Dec 2007 16:40:55 +0000, Peter Clinch wrote:
> > d...@even.ask wrote:
>
> >> 1) Put bathroom scales in bath
> >> 2) Put ruckack liner in rucksack
> >> 3) Put rucksack on scales and weight it
> >> 4) Fill liner with water
> >> 5) Note weight on scales
> >> 6) Calculate volume from weight difference
> >> 7) Upend rucksack extracting scales and sack a.s.a.p.
>
> >> Now what could possibly go wrong? ;-)
>
> > Problem is if the water gets out it'll go everywhere as it's too runny,
> > but if you were to use something a little thicker, like, say, tomato
> > ketchup... ;-)
>
> > Pete.
>
> Make sure the bath's clean, use beer (or whatever you like), then a leak's
> an opportunity, not a problem[1].
>
> [1] ensure plug is in.
> --
> Peter.
> You don't understand Newton's Third Law of Motion?
> It's not rocket science, you know.

Interesting - 40 L = 84 pints; isn't that what one normally gets in a
barrel ? Gives a new meaning to having it on tap ! And I've never
really favoured one of these bladders, but a 40 L one full of beer,
now that is a good idea.

Rob