CLINICAL LAB SCIENEC

CHAPTER 8: PIPETTING AND USE OF GLASSWARE 189
Meniscus
Liquid
A
B
FIGURE 8-3 (A) Volumetric flasks. (B) Determining measurement in a volumetric flask.
Source: Delmar/Cengage Learning.
the line. This flask is similar in function to the Griffin beaker but with a narrow
neck rather than the vertical walls of the Griffin beaker. This type of top enables
the Erlenmeyer flask to be stoppered with a rubber bung or with cotton or steel
wool. The contents of an Erlenmeyer flask can be easily swirled or stirred during
a procedure without spilling. The flat bottom aids in avoiding tipping over and
easily fits onto the ring stand for a Bunsen burner or other electronic heating
device such as a hot plate.
Griffin Beaker
The Griffin beaker is slightly less accurate for measurements
than the Erlenmeyer flask. Usually it also has designations
for volumes of a semiquantitative nature on
the walls of the beaker (Figure 8-5). These containers are
chemically inert and thermally stable, particularly those
constructed of glass. A small spout on the lip allows for
easy pouring to another container. These containers are
most often used for heating materials, melting substances,
or mixing liquids that are premeasured and require mixing
before their use or where less exactness of the volume
of liquid is needed.
Graduated Cylinder
Graduated cylinders are also used for minimally accurate
measurements of liquids in larger amounts than the
FIGURE 8-4 Pyrex Erlenmeyer flask starter pack.
Source: Delmar/Cengage Learning.
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