How To Choose A Muffle Furnace

A muffle furnace is commonly found in laboratories that carry out high-temperature applications such as annealing, quenching and tempering on small steel components. These furnaces are vital instruments in the industrial and mining industries and play an important role in research and development laboratories where materials need to be analysed. Like any instrument, they have to be configured to suit your requirements. A muffle furnace is no different; therefore, throughout this article, we will outline the key aspects to consider when choosing a muffle furnace. 

An Overview of a Muffle Furnace

When high-temperature applications are carried out in a furnace, there are risks of contamination from the fuel and byproducts from the heat source. A muffle furnace was initially used to isolate the sample material from the contamination risks whilst carrying out the required analysis. However, as muffle furnaces have developed, the risk of contamination is lower due to an electric heat source being used instead of coal or other fuels. A more in-depth look at a muffle furnace can be found on our blog.

What to Consider When Choosing a Muffle Furnace 

Muffle furnaces can be designed with various features and configurations, and it is essential to identify the most necessary for your applications. Whether the furnace material or integrated safety features are most important to you, consider some of the critical aspects.

Chamber Size

To ensure the muffle furnace you choose can support the sample size and weight, you need to consider the chamber size. Your samples need to fit into the chamber with enough room for the process to be carried out, but if a chamber is too big, they become less energy efficient as empty space is being heated. 

Door Opening Options

This might not be a priority for everyone, but the way the door opens on a muffle furnace could provide certain advantages or disadvantages. The first thing to consider is how much space is available or what set-up is in place in your lab. Secondly, if the furnace is used in an educational setting, a door that slides upwards is often considered safer than other configurations.

Heating Element

Three common heating elements used in muffle furnaces correspond to specific temperature ranges. For working temperatures below 1200oC, a resistance wire is used. Operating temperatures of 1300-1400oC utilise silicon carbide rods, and silicon molybdenum rods are used for temperatures between 1400-1700oC. 

Power Supply

Check which power supply the muffle furnace is manufactured with, as some may be designed for specific regions. 

Software

If the installed programable controls or software is essential to you, check what options are available. Typically, a muffle furnace will be configured with the option to set and monitor the temperature, but more advanced settings are available if alarms, timers and other options are required. 

Working Temperature

The most crucial factor to consider is a muffle furnace’s minimum and maximum temperature. It would help if you chose a furnace that will reach the desired temperature for your applications because although standard muffle furnaces operate at 1100oC, in material testing, it is common for furnaces to require a working temperature of up to 1400oC.

XRF Scientific Muffle Furnaces

XRF Scientific supplies a range of muffle furnaces ideal for materials research, testing and other high-temperature applications. We provide two ranges of muffle furnaces, which are determined by the kanthal wire elements within the furnace lining (wound or embedded).

The benefits of the muffle furnaces XRF Scientific supplies are their optional overtemperature monitoring add-on, robust design and working temperatures of 1050 – 1200oC. 

Contact us today for more information on the muffle furnaces we provide or with any questions you might have.