Standard Operating Procedures

Muffle Furnace


The muffle furnace is a well insulated oven with a maximum temperature of 1100 °C. It is typically used in baking and/or sterilizing materials and glassware. It is critical to know the location of the thermocouple and to know the melting point of whatever you are putting inside it.


Muffle furnace thermocouple
Muffle furnace thermocouple
Muffle furnace controller
Muffle furnace controller
  1. Place items CAREFULLY inside furnace and do not disturb or bump the thermocouple in back of the furnace.
  2. Once the oven is filled with whatever is going to be baked, make sure the door is completely closed.
  3. If the oven is not already on, use the switch to turn it on.
  4. There is a digital reader on the bottom left under the door. Using the up arrow, change the green number up to the desired temperature.
  5. Make sure the desired temperature is not past the melting point of any of the materials put inside the furnace.
  6. Press the blue button to set the temperature.
  7. It will take about an hour to reach the desire temperature.
  8. Fill out the Sign-In Sheet for the Muffle Oven.


  1. Once the furnace has been at the desired temperature for the desired amount of time, set the temperature down to below 20 °C using the down arrow to change the temperature and blue button to set.
  2. Do not attempt to open the door until the temperature is 100 °C or below.
  3. Do not attempt to take any materials out of the oven until the digital screen is around 25°C unless you are using gloves and the temperature is under 100°C. Cooling the oven takes longer than heating the oven up.
  4. Once the materials are cool, remove from the oven and store in its respectable spot.
  5. Close the oven door.


  1. Pyrex - 500 °C - at least one hour
  2. Quartz - 1000 °C - at least one hour
  3. Fritted funnels - 480 °C - less than one hour
  4. Heated gases - 1025 °C - at least 2 hours


  1. Do not put plastic in the oven.
  2. Keep corrosive materials away from the furnace.
  3. Never put explosives or highly reactive materials into the furnace


  1. If you find a fire burning inside, get the fire extinguisher, located by the doors in both room 303B and 302A, put out the fire and leave the room until the air is sufficiently cleared.
  2. If you are unable to put out the fire, pull the alarm and get out.


  1. If you smell something strange coming from the muffle furnace, turn off the oven and carefully open the door to determine the source. Turn furnace off and remove contents as needed.
  2. If the controller displays ‘b.o’ this means ‘burn out’ and the thermocouple is probably dead, check resistance