Beakers are simple containers, usually cylindrical with flat bottoms and a lip for pouring. They are manufactured in various sizes and materials. Beakers are used for stirring, mixing, measuring, and heating liquids in a laboratory. This video shows several uses.
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ASTM International provides specifications for five types of glass beakers, which generally break down into low form, tall form, and electrolytic. Low form (Griffin) beakers are 1.4 times as high as they are wide. Tall form (Berzelius) beakers are about twice as high as they are wide. Electrolytic beakers allow an electrical current to pass through the substance to produce a substrate.
A flat beaker or crystalizer features a greater surface area for more uniform heating/boiling out of liquids and better extraction of solids.
Volume: Beakers can range in capacity from as little as 5 ml to as great as 10,000 ml.
Diameter: These specifications range from as small as 20 mm to as large as 230 mm (outside).
Material: Beakers come in various materials. In general, glass beakers have greater chemical and temperature tolerances, and are easier to sterilize. Plastic beakers are safer (little or no breakage), lighter, easier to store, and less costly. Metal beakers are safe, but are opaque and tend to be costly.
- Glass: The most common material is borosilicate glass, which has a low expansion coefficient, excellent thermal performance, and high resistance to chemical attack. Pyrex (Corning) and Kimax (Kimble) are borosilicate glass brand names.
- Plastic: Some beaker plastics and common properties are ethylene-chlorotrifluoroethylene (ECTFE) (translucent, excellent chemical resistance, low temperature resistance; Halar is a Solvay Solexis brand), polyethylene (PE) (semi-opaque, excellent chemical resistance, low temperature resistance), polymethylpentene (PMP) (transparent, excellent chemical resistance, temperatures up to 150°C, autoclavable; TPX is a Mitsui Chemicals, Inc. brand), polypropylene (PP) (semi-opaque, superior chemical resistance, temperatures up to 121°C, autoclavable), or polytetrafluoroethylene (PTFE) (semi-opaque or opaque, significant chemical resistance, temperatures up to 260°C; Teflon is a DuPont brand). Careful consideration should be paid to the specific properties of whatever plastic is used.
- Metal: These beakers are opaque, lightweight, durable, and easy to clean. Aluminum beakers can be heated up to 340°C; stainless steel beakers are safe up to 550°C.
Disposable: These beakers are intended for one-use or limited use.
Graduated: Flasks are often marked with lines indicating volume, but are not intended for accurate measurement. This video discusses measuring volume in flasks and other labware.
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Handle: Handles ease carrying and pouring, but are unusual outside plastic ware.
Heavy duty: These beakers have thicker walls, heavier bases, and reinforced rims and spouts. They are designed for longer life and safety, and are less prone to breakage.