How to Measure a Volume Graduated Cylinder

Concave menisicus (A) and convex meniscus (B)

A graduated cylinder is a container used in laboratories to obtain precise volume measurements for liquids. When liquids are poured into a graduated cylinder, the top surface of the liquid is not level. It forms a meniscus, or curvature. If the meniscus is concave, or pointing downward, then the bottom of meniscus is where the volume level is read. For a convex meniscus, or upward pointing meniscus, the volume level is read at the top of the curve.

Things You'll Need

• Graduated cylinder
• Liquid to measure
• Pipet (if necessary)

Instructions

1. Pour liquid into the graduated cylinder slowly until approaches the measurement mark you desire.

2. Check the measurement to determine if there is too much or too little liquid. Remember to read the correct part of the meniscus depending on whether it is concave or convex. The only way to to this accurately is to take the reading at eye level with the level of the liquid.

3. Adjust the fluid level and take another reading. If there is too much liquid, you can either pour some out or, if you need more precision, use a pipet to draw some out. If there is not enough, you can pour some more in or drip it in using a pipet.

4. Repeat until you have the amount of liquid you are trying to obtain.