Selecting a Vacuum Desiccator on Amazon.com
Desiccators are used in laboratory, research, clean rooms, and electronic applications to dry or protect items such as film, delicate circuits, and pharmaceuticals from dust and moisture. Vacuum desiccators have an airtight chamber with a stopcock that allows air to be pulled from the chamber. Most vacuum desiccators can also be used as a standard, non-vacuum desiccator by using a desiccant and closing the stopcock. While vacuum desiccators work by pulling air from the chamber, gas-purge desiccators remove moisture-laden air by introducing a dry, inert gas such as nitrogen.
Vacuum desiccators are often used for storing materials at extremely low humidity or materials that are sensitive to air. They range in size from compact and portable tabletop models to large floor-standing models. Some are stackable, enabling users to expand capacity as their needs change. Usually made from glass or polypropylene materials, some models are composed of opaque materials that add a layer of protection for light-sensitive materials. Glass is transparent for observation without opening the chamber, is chemically inert, and cleans easily. While glass is sensitive to changes in ambient temperature, polypropylene and other laboratory-grade plastics are resistant to chemicals and temperature fluctuations. Spherical or dome-shaped models are accessed from the top and are usually used when contents need to be observed, while cabinet-style models are accessible from the front and can often be stacked, allowing users to expand capacity as the demand requires. Grease is often used on the stopcock and other openings to ensure a tight seal.
Factors to consider when choosing a vacuum desiccator include location and available space, required capacity and possible expansion needs, whether the unit needs to be portable, and proximity to a vacuum pump. It is also important to consider whether the contents need to be observable or require protection from light.