Pack Volume.

[MisterSweetie]

I have an old Gregory pack that I have no information on. No name, nothing. In fact, it may even be a womans pack (I'm a mister, not a sister). I love the pack basically, but I think it's somewhat on the heavy side, and low volume side. The volume isn't a problem, the weight would be. If someone has vast knowledge of Gregory products, I can get some pics of the pack up here.

So two questions.

First, is there a good way to test the volume of the pack? I don't care per se, except that I'm in the market for a new lighter pack, and I want to get one about the same volume as I have now. I can think of a few ways, but none are easy or convenient.

Second, is there a convenient way to get an accurate weight on [empty] backpacks?

Thank you all!

[Uncle Silly]

weight: postal scale. or even a bathroom scale will give you an idea: weigh yourself with pack on, weigh yourself without pack on, do the math.

volume: empty gallon (or even half-gallon) milk jugs, or liter water bottles, or something similar. see how many fit in the pack, then add up the volume of the bottles. most packs are rated in cubic-inches and/or liters. there are some good unit-conversion tools on the web you can use to go from gallons or liters to cubic-inches.

i'm not sure how the manufacturers rate their pack volume, so this procedure might not be ideal. if the pack has a model #, you could try searching for gregory's stats through google.

[Toolshed]

Go to the Walmart or UPS store and get a bunch of foam peanuts. Put an empty garbage bag inside your pack and fill it with the foam peanuts (or you could bribe the guy at the UPS store to fill your pack with foam peanuts and then take them back afterward)
Use a 1 litre (or 1 quart) container to empty the peanuts back out. take the number of quarts and convert to litres. Take the litres and multiply by 6 and you have Cubic inches (i.e. 50 litres is 3,000CI) - This gives you volume of the pack.

[MisterSweetie]

Go to the Walmart or UPS store and get a bunch of foam peanuts. Put an empty garbage bag inside your pack and fill it with the foam peanuts (or you could bribe the guy at the UPS store to fill your pack with foam peanuts and then take them back afterward)
Use a 1 litre (or 1 quart) container to empty the peanuts back out. take the number of quarts and convert to litres. Take the litres and multiply by 6 and you have Cubic inches (i.e. 50 litres is 3,000CI) - This gives you volume of the pack.Thanks, this is something I can do. I think I have enough peanuts at work for this.

Thanks for the other suggestions too!

[Uncle Silly]

Go to the Walmart or UPS store and get a bunch of foam peanuts.


Use a 1 litre (or 1 quart) container to empty the peanuts back out.

Toolshed, that's brilliant. A simple and effective method for determining the volume of an irregular space. Thanks.


Take the litres and multiply by 6 and you have Cubic inches (i.e. 50 litres is 3,000CI) - This gives you volume of the pack.

:-?
Your conversion factor is missing a zero -- you need to multiply by 60 to get cubic inches. (Technically it should be 61.03, but as we're estimating anyways...)

[Youngblood]

Scotsghost, you made me get out my old Physics book to look up the conversion, which isn't too hard since it is within reach under a bunch of CDs on the top shelf of my computer desk. Good catch, by the way! Mine had 61.02 as the conversion factor for liters to cubic inches, guess that was slide rule accuracy in my book. Anyway, for what it is worth the conversion for quarts to cubic inches is 57.75.

[Uncle Silly]

well, i was tryin' to avoid researching the conversion factor myself, but your post made me break out Google and find a conversion site. i don't know why but for some reason "50 * 6 = 3000" struck me as a little off... :D

i remember doing these conversions in physics and chem classes the hard way ... you know, start with a volume in Liters, and convert to cubic-inches by deriving the conversion from length ("2.54 cm = 1.00 in"). what a PITA!!

sorry you had to dust off the old books .. btw, your physics book seems accurate; a quick look at the calculator gives 61.023744... my 61.03 figure was copied from another website and (lazily) unchecked. wheee! math fun!