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. For instance, a 250 mL beaker might be marked with lines to indicate 50, 100, 150, 200, and 250 mL of volume. Alternatively, a beaker may be covered with another larger beaker that has been inverted, though a watch glass is preferable.īeakers are often graduated, that is, marked on the side with lines indicating the volume contained. 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. The presence of a spout means that the beaker cannot have a lid. These beakers usually do not have a flat scale. Flat beakers (C) are often called "crystallizers" because most are used to perform crystallization, but they are also often used as a vessel for use in hot-bath heating. : a large drinking cup that has a wide mouth and is sometimes supported on a standard. These are sometimes called Berzelius beakers, after Jöns Jacob Berzelius, and are mostly used for titration. "Tall-form" (B) beakers have a height about twice their diameter.
Low form beakers are likely to be used in some way when performing a chemical experiment. These are the most universal character and are used for various purposes-from preparing solutions and decanting supernatant fluids to holding waste fluids prior to disposal to performing simple reactions. The common low form with a spout was devised by John Joseph Griffin and is therefore sometimes called a Griffin beaker. Standard or "low-form" (A) beakers typically have a height about 1.4 times the diameter.
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