Precautions to be taken when using muffles in the laboratory

Muffle is a kind of furnace normally used for melting metals and for cooking materials using thermal energy. The operation of this equipment is based on high temperatures, this is possible thanks to the fact that it is made up of a closed chamber, which is covered with a refractory material that enables a uniform heat delivery inside, being able to reach temperatures of up to 1,700ยฐ C. On the other hand, the muffle operates in a more controlled way than that of a conventional oven, since it monitors and regulates the temperature at all times.

The muffle carries out thermal processes to improve the properties of hardness, wear, stamping and resistance to shock attraction. Due to its design, it has a large number of applications in different areas such as control processes, laboratory work, heat treatment, precipitation drying, precipitation calcination and smelting tests.


In every scientific laboratory we find the presence of very useful instruments and devices, among them, the muffle, which is basically an oven that operates at high temperatures, differing only from the conventional by the fact that it can heat up to 1,700 ยฐ C approximately.ย  This equipment is essential for the elaboration and baking of ceramic pieces and different purposes within the laboratory.

The muffle is constructed of insulating refractory material, which means that it is designed to withstand high temperatures and to introduce only such materials. This chamber has a viewing hole and a roof where there is a hole where gases are expelled from the chamber. In addition, it has a control mechanism that allows progressive regulation of the temperature increase.

Types of muffles

The application of the muffle in laboratories is convenient when it is desired to reach temperatures higher than 350ยฐ C. Only refractory materials should be used inside the muffle as they are the only ones that withstand the temperatures that develop in it. On the other hand, it should be taken into account that there are varieties of types of muffles, for example, fuel muffles, electric muffles or those that are based on other principles, however, all are composed of an internal cabinet, an external cabinet, the control panel, the backdoor and the temperature controllers. The types of muffles are explained in more detail below:

  • The electric muffle:ย has as function to heat solid samples and generate chemical and physical reactions, as a result of the increase of temperature. Because it heats quickly, efficiently and homogeneously, it allows to perform laboratory functions such as relay, tempering, chemical reactions, among others.
  • The fuel muffleย is, technically, an oven that operates at high temperatures and where the heat source is separated from the cooking chamber, so that it is not contaminated with the combustion gases.

Precautions to be taken when using mules in the laboratory

The muffle is a closed high-temperature chamber that is responsible for heat treatment, incineration of organic and inorganic samples, calcination tests and cooking of ceramic materials. This equipment should always be used indoors, at an ambient temperature of approximately 15ยฐ to 40ยฐ C and an average humidity of 80%. Failure to comply with these guidelines, in addition to the fact that the temperature range and stability of the equipment may be adversely affected, may also endanger workers.

When operating the machine, the worker must take the necessary precautions, such as wearing gloves and an apron, in order to verify that the mule is properly connected to the power source and to load the desired samples for processing. When the temperature has been adjusted, there cannot be near the laboratory personal muffle without the above protection. In addition, the following maintenance steps must be completed in order for the muffle to last:

  • Once a week, external cleaning with abrasive solution.
  • Periodically perform a check on the electrical system of the laboratory.
  • Avoid connecting the muffle to electrical connections that lead to overheating.
  • Keep 15 cm of free space around the muffle so that heat can circulate.
  • Recalibrate once a year to correct mismatches.

Muffle brand Kalstein

Atย Kalsteinย you will get it, as we are MANUFACTURERS of these and a wide variety of laboratory instruments. Our products have as a distinctive feature the being of wide technology and high quality, also have the best PRICES in the market, which are adapted to you and your pocket. We have Universal Lab High Temperature Box Muffle Furnace and Muffles. Our models Universal Lab high temperature box muffle furnace have the following features:

  • 1200ยฐC, 1400ยฐC, 1700ยฐC maximum operating temperature.
  • High purity fibrous alumina insulation for maximum energy saving.
  • Double layer steel structure with air cooling fan to keep the outside of the oven safe to the touch.

If you wish to purchase any of the mules we have available for sale, you can access:ย HEREย . To view our other products and equipment, seeย HERE