Net weighing

Auger, SFW, net-weigh 1 Sewn valve bag 16x5x28 405 X 125 x710 4-190 Tuck-in sleeve PE 32 513 %2-in cubes... 

There are various reasons for weighing materials and various methods employed the most common ones are discussed below. It is assumed for the sake of discussion that net weight is the requirement, since it is the more common. 

Weighing the loaded car on a coupled-in-motion track scale. An entire train, typically, is hauled at slow speed over the scale. The net weight is determined by subtracting the tare weight stenciled on the car... 

SoHd carbon dioxide is produced ia blocks by hydrauHc presses. Standard presses produce blocks 25 x 25 x 25 cm, 50 x 25 x 25 cm, or 50 X 50 X 25 cm. A 25-cm cube of dry ice weighs 23 kg, allowiag for about 10% sublimatioa loss duriag storage and shipment (some 27-kg blocks are also produced). Dry ice is about 1.7 times as dense as water ice, whereas its net refrigerating effect on a weight basis is twice that of water ice. Automation and improved operating cycles have iacreased dry-ice press capacities so that one 50 x 50 x 30 cm press can produce more than thirty metric tons of dry-ice blocks per day (42). 

Nordherg Inc. Assumes feed weighing 100 Ih/ft and with a work index of 13. A—Net finished product from screen. 

The weighing and proportioning of liquids and solids has also benefited from this technical revolution. Sensing devices and special-purpose computers give a level of precision and speed not possible in the era of elec tromechanical devices. The net result is that packaging and material handling systems now have the sophistication of chemical processes. 

Feed gate fully open. 97% of net weight enters weigh vessel. 

Weigh vessel contains the net weight called for on the package label. 

If an option proves to be technically ineffective or inappropriate, it is deleted from the list of potential alternatives. Either follo ving or concurrent with the technical evaluation, an economic study is performed, weighing standard measures of profitability such as payback period, investment returns, and net present value. Many of these costs (or, more appropriately, cost saving may be substantial yet are difficult to quantify. (Refer to Economic Considerations Associated with Pollution Prevention.)... 

The net ionic equation, like all balanced chemical equations, gives the ratio of moles of each substance to moles of each of the others. It does not immediately yield information about the mass of the entire salt, however. (One cannot weigh out only Ba2+ ions.) Therefore, when masses of reactants are required, the specific compound used must be included in the calculation. The use of net ionic equations in stoichiometric calculations will be more important after study of molarity (Chap. 10). 

To remind yourself how to weigh samples accurately, watch the video clip at www.brightredbooks.net... 

At least semiannually, all high-pressure cylinders should be weighed and the date of the last hydrostatic test noted. If, at any time, a container shows a loss in net content of more than 10%, it should be refilled or replaced. 

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