The core of the use of muffle furnace is "safe operation + precise temperature control + standardized process", which must follow the four-step specification of "preheating inspection → sample loading settings → start operation → cooling and pickup".  1. Preparation before use Check whether the appearance of the equipment, power cord and grounding are intact, make sure there are no debris in the furnace and the heating element is not damaged.  Clean oil, moisture and other volatile substances on the surface of the sample to avoid harmful gases or explosions when heated.  According to the sample requirements, select an appropriate crucible (ceramic, quartz, etc.) to ensure that the crucible is not damaged.  Turn on the power switch, preheat the control system, and confirm that the temperature display and alarm functions are normal.  2. Sample loading and parameter setting. Place the sample evenly into the crucible. The height of the sample should not exceed 2/3 of the crucible volume to avoid overflowing during heating.  Use crucible tongs to place the crucible in the center of the furnace, ensuring that the sample does not contact the inner wall of the furnace or the heating element.  Close the furnace door and lock it tightly to ensure that the furnace is well sealed (the gas protection type needs to connect the protective gas and exhaust it in advance).  Set temperature parameters: Enter the target temperature, heating rate (generally 5-20℃/min), and holding time through the control panel.  After confirming that the parameters are correct, start the heating program, and the equipment will automatically heat up according to the set curve.  3. Monitor the operation process. Closely observe the temperature rise in the initial stage of heating. If the temperature fluctuates abnormally or alarms, immediately suspend equipment inspection.  During the heat preservation stage, check the control panel display regularly to ensure that the actual temperature is consistent with the set temperature.  It is forbidden to open the furnace door during operation (high temperatures can easily cause burns and affect the temperature field). If you need to observe, you can use the furnace door observation window.  Gas-protected equipment needs to continuously monitor gas flow and pressure to avoid gas interruptions that may lead to sample oxidation.  4. Cooling and picking up After the heat preservation is completed, the equipment automatically enters the cooling stage (or manually sets the cooling rate). Rapid cooling is prohibited (it can easily lead to furnace cracking).  The furnace door can be opened only when the furnace temperature drops below 200°C (some high-temperature models need to drop below 100°C).  Use high-temperature resistant crucible pliers to slowly remove the crucible and place it on a heat-resistant platform to cool naturally to avoid contact with a cold tabletop, which may cause explosion.  After the pickup is completed, turn off the power switch, clean the remaining debris in the furnace, and keep the equipment clean.  5. Safety precautions: Wear high-temperature-resistant gloves and protective glasses during operation to avoid high-temperature burns or injuries from sample splashing.  It is prohibited to heat flammable, explosive, corrosive or volatile samples to prevent safety accidents.  Keep the area around the device well ventilated, keep away from flammable materials, and reserve space for heat dissipation (at least 30cm).  Regularly check the heating elements, insulation layer and power cord. If any damage is found, stop the machine immediately for repairs. It is prohibited to operate the machine when it is sick.