Vacuum Oven units heat and dry samples inside an airtight chamber under reduced pressure. An external vacuum pump sets the vacuum level, so moisture and solvents leave at lower temperatures. Vacuum drying avoids high heat that can damage or oxidize a sample. Chamber size and temperature range vary by model. Chamber volume runs from 20 L to 252 L. Six models reach 200 C. Two reach 250 C, and one reaches 400 C. Models that list shelves have 2 or 3. Stainless steel chambers appear on two models. One model offers a timer up to 9999 min and a vacuum below 133 Pa. Pharmaceutical, electronics, materials and chemical labs use vacuum ovens to dry powders, coatings and heat-sensitive samples.