Beakers

Beakers are simple cylindrical-shaped containers used to hold reagents or samples for scientific experiments. They are usually made of glass since it is relatively inert, transparent, heat-resistant and easy to customise. The glass is borosilicate glass or sodalime glass manufactured to withstand thermal stress. In size they vary from one millilitre to several litres and are often graduated with lines to show the volume. They are not as precise as graduated cylinders so the lines are for estimating only. Some may have a small spout (or beak) to aid pouring and may be covered by a watch glass to prevent contamination. Standard or low form beakers, also known as Griffin beakers, have a height that is 1.4 times the diameter. Tall-form, also called Berezelius beakers, have a height which is double their diameter. Flat beakers or crystallisers can be used as containers in hot-bath heating. Most are straight without sloping sides but the exception is the slightly conical-sided Philips beaker. Standard beakers are the most universally used to prepare solutions, mix liquids, decant supernatant fluids, perform simple reactions and hold waste fluids prior to disposal. Tall beakers are mostly used for titration while flat ones are used for crystallisation.