The 6 Best Vacuum Desiccators
Editor's Notes
October 10, 2019:
The easiest way to understand a vacuum desiccator is to consider it a sort of hybrid between a standard desiccating chamber and a vacuum chamber. Desiccant chambers employ a desiccating agent (quite often silica) to absorb any moisture floating through the air, and typically reduce the relative humidity within the chamber to around 25%. Vacuum chambers employ vacuum pumps to suck moisture out of them and create a pressurized atmosphere for an extended period. Vacuum desiccators do both.
A few things to look for while you’re shopping this category:
Volume: With tiny options ranging from the six-inch-diameter CB 1354150, to the 65-liter SP Scienceware 42029 – which can house samples as tall and as wide as 18 inches – the utility offered by these devices will vary considerably. Possible shelving configurations is another consideration that comes into play when considering a given unit’s total capacity. Your needs in terms of capacity will, of course, depend completely on your intended uses for the machine, but it rarely hurts to err on the side of bigger.
Airtightness: While any of the products in this category should, by design, be able to maintain vacuum conditions, for how long is a different question. 24 hours seems to be the accepted benchmark for excellence in this respect, but some offerings can go longer, including the Bel-Art F42400-4001, which can maintain a vacuum for over 72 hours.
Gauges: Though these come standard on vacuum chambers, as well as vacuum ovens, they’re much less common in this category. I must admit, especially when considering the threat to safety that’s posited by the possibility of implosion, that this seems like a careless oversight. Though admittedly more expensive, options like the Cleatech 1300-2-A-G, that include an integral pressure gauge, will give you the peace of mind and confidence that comes with knowing you’re maintaining ideal vacuum conditions within your desiccator.