A graduated cylinder is used to measure liquid volume. The unit is the milliliter (mL). To use a graduated cylinder, you must remember the following:

- Place the graduated cylinder on a flat surface and view the height of the liquid in the cylinder with your eyes directly level with the liquid. The liquid will tend to curve downward. This curve is called the meniscus. Always read the measurement at the bottom of the meniscus.
- Graduated cylinders come in many different sizes (including 10 mL, 25 mL, 50 mL, 100 mL, 500 mL and 1000 mL) and can be marked with different scale increments. It is important to determine the scale increment before you begin to measure. To find the scale increment, subtract the values of any two adjacent labeled graduations and divide by the number of intervals between them. This technique works for thermometers, spring scales, and any other measuring instrument as well.

The graduated cylinder will usually have heavy markings at 10, 20, 30 . . . milliliters. There are usually smaller markings in between the larger units called graduations. Read the graduated cylinder to the nearest tenth of a milliliter (46.5 mL or 20.0 mL).

For example:

15 – 10 = 5 (subtract the values of two adjacent labeled graduations

5/5= 1 (divide by the number of intervals between them)

So each graduation on the cylinder is 1 mL

**You Try!**

Determine the volume. Remember to determine what the scale increment is first and then read from the bottom of the meniscus.