How is the volume of a backpack determined?
Remembering geometry lessons
We are based on the fact that the backpack has the shape of a rectangle. This statement, of course, is very approximate, because some accessories have a trapezoidal or rounded shape, many pockets. We measure the length, width and height; we bring to a single unit of measurement; multiply and get the result — the volume in the cube. m. Example: a backpack has the following overall dimensions: 0.48 m; 0.37 m; 0.12 m. The volume of the product is 0.48 x 0.37 x 0.12 \u003d 0.021 cubic meters. m. Next, we solve the proportion:
1 cu. m — 1000 l
0.021 cc m — the volume of the backpack in liters
Backpack volume \u003d 0.021 x 1000 \u003d 21 liters, and this is far from an accurate result, but it is fast. Corrections will have to be made by eye.
We call on the help of Autocad
Autocad is a program used by engineers, architects, and designers. With its help, you can calculate the volume of three-dimensional solids with high accuracy, including those that are irregular in shape. The task of the user is to correctly indicate the original linear dimensions; The program calculates the volume itself. The disadvantage of the method is that it is available only to people with special training.
Use a thick plastic bag
The bag must be taken the largest and thickest — of those in which construction waste is placed. We place it inside the backpack, straighten it in such a way that the lower part coincides with the bottom of the product, and the upper part remains outside. Pour water, measuring with a liter jar, until we fill the backpack.
For obvious reasons, such experiments should be carried out in the bath, and not in the middle of the room on the parquet floor. The backpack will fit a volume of water equal to the volume of the product. This is a fairly affordable way to measure, but in the absence of a skill it is fraught with surprises (the bag breaks, water pours out). In addition, the volume of external pockets is not taken into account.
Playing with sand
Another simple way to measure displacement is to use sand. It, like water in the previous version, is poured into a plastic bag with a liter jar, or a backpack is filled with liter bags of packaged sand, which is sold in hardware stores. In the case of packages, the error should be taken into account, since gaps remain between them in any case.
If the product is new and the bags are not tight enough, they may break. The sand will begin to crumble, get stuck in the seams and corners, which is highly undesirable. And again, the pockets remain outside the calculations, which distorts the result.
We measure the volume with balls
The most accurate way to determine displacement involves measuring with balls. Universal loose filler is poured into internal compartments and external pockets. The balls fit tightly to each other, do not spoil the product and do not leave debris behind. It is this method that is used for Grizzly backpacks and knapsacks. Knowing the volume of one ball and their total number, it is easy to calculate the volume of the backpack. The result will be the most accurate of all possible.
What volume do you need?
Finally, a few words about what size backpacks are appropriate in a particular case.
— Small products (up to 15 liters) are popular with girls. A cosmetic bag, a tablet, a purse — that’s the whole «luggage» of an elegant women’s accessory.
— Men’s backpacks (up to 35 l) are suitable for lovers of an active lifestyle. They fit sports uniforms, skates, and look stylish at the same time.
— Camping (50-60 l and more) will be useful for traveling and hiking in the mountains.
Are you planning to buy a new backpack and don’t know what size to choose? Try to determine the displacement of the old one using the methods described here. This will help you make the right choice.
Liked the article? Share with friends!