Corporate Buyers Guide

The lab box furnace and lab muffle furnaces differ in where the heating elements are located. The box shaped furnaces need strong heat sources to achieve the desired temperatures.

The heat source is mostly from electric heating elements. Resistance wire or rod like heating elements are located at, or fastened to the furnace walls. Resistance wire, straight or coiled is sometimes buried into the wall with furnace cement. This is primarily to prevent dirt from collecting on the wire and create hot spots which cause the wire to melt. This is a simple inexpensive method of creating a heat source.

If it is important to keep the product being heated away from the heat source, a graphite or ceramic container is inserted into the oven. This container is called a muffle. Depending on the amount of sealing around the muffle, it prevents particles or vapors from reaching the heating elements. The muffle furnace is a more complicated design and therefore more expensive.

The laboratory oven is an essential tool in any chemical or life sciences laboratory. All laboratory ovens are bench ovens, but some have added features.

The laboratory bench oven has a stainless steel interior. The outside is enamel for good appearance and easy cleaning. These ovens have a maximum temperature of about 600 F. They have one or two front doors and a maximum capacity of about 30 cu ft.

The inert atmosphere oven has a tube fitting connected to the internal liner that permits inert gases, such as nitrogen to be fed into the interior of the laboratory oven. The same liner also has openings so that the air can escape while the inert atmosphere is fed into the oven.

The lab vacuum oven has a fitting connected to the interior lining of the oven to which a vacuum pump is connected. The interior lining is strong and has no leaks. The door has a tight seal to prevent air from leaking into the oven. The strength of the interior lining and the seal around the door determine the vacuum capacity of the oven.