Conversion of "weight box" unit of measurement of flat glass
I. concept of weight box
the measurement method of ordinary flat glass is generally calculated by "weight box", which is the unit of measurement for calculating the materials and costs of flat glass. (we usually say the size of glass, generally speaking, how many square meters, but because the thickness of glass is different, the glass materials with the same square and different thickness are different. Engineers want to calculate the output, not in the unit of area, but only in the unit of weight, that is, the heavy box). A weight box is equal to 10 square meters of 2mm thick flat glass (weighing about 50kg)
we regard glass as a cube, and the weight is equal to the volume multiplied by the specific gravity.
leading step, calculate the volume, the volume of 10 square meters of 2mm thick flat glass is: 0.002m * 10 ㎡ =0.02 cubic meters
step 2: calculate the specific gravity of glass is: 2500 kg/cubic meters, which is a constant
step 3, calculate the weight of 10 square meters of 2mm thick flat glass is: 0.02 cubic meters * 2500 kg/cubic meters =50kg
step 4, Comprehensive (0.002m*10 ㎡) *2500kg/cubic meter =50kg
II. Conversion between the number of glass heavy boxes and square numbers
if you are an engineer, statistics tell you that the output of 4mm glass this month is 1500 heavy boxes, can you know how many square meters it is? This is to calculate the area, or take the glass as a cube. The area is equal to the volume divided by the height. The height here is the thickness of the glass
let's go step by step,
second, the control panel checks the leading step, calculate the volume, or the above formula, weight = volume * specific gravity, push back, volume = weight/specific gravity. The volume of a 1500 heavy box is 1500*50kg/2500=30 cubic meters
step 2, calculate the area of 30 cubic meters/0.004=7500 square meters
third, how many square meters can be produced by different thicknesses of glass in a heavy box
take 2mm glass as an example, (0.002m*10 square meters) *2500kg=50kg, push back the square number: (50kg/2500kg)/0.002=10 square meters
similarly, 1.5mm glass: (50kg/2500kg)/0.0015=13.3333 3mm glass: (50kg/2500kg)/0.003=6.66666 ㎡ 4mm glass: (50kg/2500kg)/0.004=5 ㎡ simpler method: you can see 50kg/2500kg? It's a constant, which is 0.02. In the future, you just need to divide 0.02 by the thickness to get the square of the glass heavy box with this thickness. We evaporate the water first, and the divisor and the dividend are expanded a thousand times at the same time. The result of 0.02/0.002=20/2 is the same, that is, the square number of a 2mm glass heavy box will adjust the qualified dial to 20 divided by 2=10 square the same, The square of a 3mm glass heavy box is 20 divided by 3=6.66 square the square of a 4mm glass heavy box is 20 divided by 4=5 square the square of a 5mm glass heavy box is 20 divided by 5=4 square the square of a 10mm glass heavy box is 20 divided by 10=2 square later, when people ask you how many millimeters of glass a heavy box is, you can directly divide 20 by the thickness of the glass, but in fact, the thickness of the glass is error (generally within 0.2mm), for example, the actual thickness of 5mm thick glass is no less than 4.8mm. The above should be the minimum value (that is, the corresponding square number of standard thickness), and the specific allowable error is (building level): mm ± 0.2mm, 8mm, 10mm ± 0.3mm. Our forward-looking statement is subject to a lot of risks and uncertainties, 12mm ± 0.4mm, 15mm ± 0.5mm, 19mm ± 1.0mm. Knowing these, it is easy to convert the price of square meters of glass into the price of weight boxes
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