The term muffle furnace may also be used to describe another oven constructed on many of the same principles as the box type kiln mentioned above, but takes the form of a long, wide, and thin hollow tube used in roll to roll manufacturing processes. These furnaces allow for uninterrupted processing of materials or products in a controlled environment.
Both of the above mentioned furnaces are usually heated to desired temperatures by conduction, convection, or blackbody radiation from electrical resistance heating elements. Therefore there is (usually) no combustion involved in the temperature control of the system, which allows for much greater control of temperature uniformity.