Measuring rucksack volume ?

In article
<[email hidden]>, Rob
G <[email hidden]> writes

Quoted message said:

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

Dominic Sexton said:

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 [email hidden] http://www.dundee.ac.uk/~pjclinch/

Peter Clinch said:

Dominic Sexton said:

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 [email hidden] 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

Rob G said:

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.

Quoted message said:

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 [email hidden] http://www.dundee.ac.uk/~pjclinch/

Peter Clinch said:

Quoted message said:

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/

Peter Clinch said:

Quoted message said:

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.

PeterC said:

Peter Clinch said:

[email hidden] wrote:

Quoted message said:

Quoted message said:

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.

Quoted message said:

Quoted message said:

Now what could possibly go wrong? ;-)

Quoted message said:

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... ;-)

Quoted message said:

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

Rob G said:

PeterC said:

Peter Clinch said:

[email hidden] wrote:

Quoted message said:

> 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.

Quoted message said:

> Now what could possibly go wrong? ;-)

Quoted message said:

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... ;-)

Quoted message said:

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

Merkin pints, I assume.
Camelback - more like through the eye of the proverbial after a long walk!
--
Peter.
You don't understand Newton's Third Law of Motion?
It's not rocket science, you know.