If you care at all about having a

known or consistent volume, avoid

the temptation of using the

markings on beakers and

Erlenmeyer flasks for

measurements of volume.

Graduated Cylinders

Graduated cylinders are tubes with

marks that indicate specific

volumes. Graduated cylinders

come in a variety of sizes, and the

uncertainty associated with the

graduated cylinder depends on the

size of the cylinder and the markings. Advantages of graduated cylinders are that

they are relatively quick and easy to use and that they also allow for the

measurement of any volume within the range of the cylinder. For example, the

100 mL graduated cylinder pictured below could be used to record any volume

between 10 and 100 mL.

To use a graduated cylinder, you

simply fill the cylinder with a liquid

and then read the liquid level using

the marks on the side of the

cylinder. You will notice that the

liquid surface is not flat at the top

but instead curved as the water

adheres to the glass walls of the

cylinder. The curved surface of the

liquid is called the meniscus. The

liquid level is read at the bottom of

the meniscus in order to have a

consistent measurement standard.

Notice that in figure 3.6 the edges

of the meniscus are between 19

and 20 mL but the bottom of the

meniscus is between 20 and 21

mL.

25

Figure 3.4: Volume measuring container at a hospital.

Figure 3.5: Graduated Cylinder: "Laboratory Equipment -

Graduated Cylinder" by eltpics is licensed under CC BY-NC

2.0.