Shape
Beakers are often graduated, that is, marked on the side with lines indicating the volume contained. For instance, a 250 mL beaker might be marked with lines to indicate 50, 100, 150, 200, and 250 mL of volume. These marks are not intended for obtaining a precise measurement of volume (a graduated cylinder or a volumetric flask would be a more appropriate instrument for such a task), but rather an estimation.
The presence of a lip means that the beaker cannot have a lid. However, when in use, beakers may be covered by a watch glass to prevent contamination or loss of the contents, but allowing venting via the spout. Alternatively, a beaker may be covered with another larger beaker that has been inverted, though a watch glass is preferable.
Read more about this topic: Beaker (glassware)
Famous quotes containing the word shape:
“There are moments when very little truth would be enough to shape opinion. One might be hated at extremely low cost.”
—Jean Rostand (1894–1977)
“There are men from whom nature or some peculiar destiny has removed the cover beneath which we hide our own madness. They are like thin-skinned insects whose visible play of muscles seem to make them deformed, though in fact, everything soon turns to its normal shape again.”
—E.T.A.W. (Ernst Theodor Amadeus Wilhelm)
“Strange that so few ever come to the woods to see how the pine lives and grows and spires, lifting its evergreen arms to the light,—to see its perfect success; but most are content to behold it in the shape of many broad boards brought to market, and deem that its true success! But the pine is no more lumber than man is, and to be made into boards and houses is no more its true and highest use than the truest use of a man is to be cut down and made into manure.”
—Henry David Thoreau (1817–1862)