A graduated cylinder is a common piece of laboratory equipment used to measure the volume of a liquid. It is a long, slender vessel with graduations to indicate the volume of liquid held, and typically a spout to ease pouring. Graduated cylinders are generally more accurate and precise than laboratory flasks and beakers, but they should not be used to perform volumetric analysis; volumetric glassware, such as a volumetric flask or volumetric pipette, should be used, as it is even more accurate and precise. Graduated cylinders are not intended for mixing, stirring, heating, or weighing. They are meant to be read with the surface of the liquid at eye level, where the center of the meniscus shows the measurement line. Graduated cylinders commonly range in size from 5 mL to 1000 mL.
To use a graduated cylinder, one should select a graduated cylinder with markings that will not be obscured by the substance being measured, made from a material that is appropriate for the substance being measured, and of the appropriate size. The volume to be measured should fall between the lowest and highest numbered graduations on the cylinder. The graduations on the cylinder should be determined by locating two consecutive labeled graduations on the cylinder, determining the value between the labeled graduations by subtracting the two values, counting the number of spaces between the two graduations, and dividing the value between the graduations by the number of spaces. The graduated cylinder should be put on a flat, level surface, and the meniscus should be read at eye level to avoid parallax.
