Vacuum ovens are commonly used for drying samples where one wants to dry sample at lowest possible temperature to avoid deterioration of the sample. Beyond sample drying, vacuum ovens are used for applications such as curing epoxies, baking-out, degassing liquids, moisture determination, aging tests, and heat treating. Vacuum pump selection depends on the oven volume, the chemistry of the vapors removed from oven, vacuum level needed for process, and the mass of those vapors removed.
For many procedures using vacuum ovens, an oil-free, standard duty, WOB-L piston vacuum pump or a chemical duty diaphragm vacuum pump offer a sufficient vacuum level to do the job. These are compact, lightweight and portable vacuum pumps. Because the vacuum pumps are oil-free, there is no oil contamination of samples, no exhaust smoke, no oil leaks, and best of all, no oil changes. Normally a liquid trap is located in front of the vacuum pump to avoid any vapor that condenses within the vacuum line from being drawn into the vacuum pump. Supplemental inlet cold traps are recommended for high water vapor loads.