Common faults and solutions of nitrogen atmosphere vacuum muffle furnace

06-04-2025       Author: KJ technology

The common faults and solutions of nitrogen atmosphere vacuum muffle furnace are as follows:

Heating malfunction

Reason for malfunction: damaged heating element, circuit malfunction, burnt or damaged solid-state relay, low voltage, etc.

resolvent:

Check the heating element: Cut off the power, open the top cover, take out an electrode connection, and use a multimeter (buzzer) to test the cooling end of each heater. If there is no sound, it indicates that the heater is damaged and needs to be replaced.

Check the circuit: Check whether the circuit connection is normal, whether there are any open circuits, short circuits or other problems, repair or replace damaged circuit components.

Check the solid-state relay: Check if the solid-state relay is damaged or if the control circuit is in good condition. If it is damaged, replace the solid-state relay.

Check voltage: Ensure stable power supply voltage. If the voltage is too low, check the power supply circuit to eliminate voltage issues.

Abnormal temperature

Reason for malfunction: The thermocouple was not inserted into the furnace, the division number of the thermocouple was inconsistent with that of the temperature control instrument, the temperature controller malfunctioned, and the thermocouple was damaged.

resolvent:

Check the thermocouple: Turn off the power and open the back cover of the muffle furnace. Check if the thermocouple is screwed onto the thermocouple lead and ensure good contact between the two; Check the open circuit status of the thermocouple sensor itself; Check if the connectors, terminals, adapters, etc. between the thermocouple end leads and the circuit board are open or incorrect, and reconnect or replace them if necessary.

Calibration or replacement of temperature controller: If the temperature controller malfunctions, it needs to be calibrated or replaced.

Unable to reach the set temperature

Fault causes: power supply issues, poor furnace sealing, insufficient power of heating elements, etc.

resolvent:

Ensure stable power supply: Check the power supply lines and power equipment to ensure that the power supply voltage and current meet the equipment requirements.

Check the sealing condition of the furnace: Check whether the sealing strip of the furnace door is aging or damaged. If it is damaged, replace the sealing strip; Check whether the connection parts of the furnace are well sealed. If there is any air leakage, repair it.

Check the power of the heating element: Check if the heating element is working properly. If the power of the heating element is insufficient, replace it with a suitable one.

Insufficient vacuum degree

Reason for malfunction: The vacuum pump is not working properly, the seals are damaged, and there are air leakage points in the furnace.

resolvent:

Check the vacuum pump: Check whether the motor of the vacuum pump is running normally, whether the pump oil is sufficient and clean. If there are any abnormalities, repair or replace the vacuum pump.

Check the seals: Check if the seals on the furnace door, observation window, and other parts are intact. If damaged, replace the seals.

Check for gas leakage points in the furnace: methods such as applying soapy water can be used to check for gas leakage points at various connection parts of the furnace. If there is a gas leakage, seal it.

Control system malfunction

Fault causes: circuit problems, controller malfunctions, communication interruptions, etc.

resolvent:

Check the circuit: Check whether the external line interface of the controller is closed or poorly connected, such as 9-pin serial port, aviation plug, etc., to ensure reliable connection and good contact; Check if the power cord of the controller is damaged.

Check the controller: If the controller malfunctions, it needs to be repaired or replaced; Check whether the switches, fuses, and travel switches of the furnace door inside the controller are normal. If they are damaged, replace them.

Check the communication line: If there is a communication interruption, check whether the communication line between the controller and the upper computer or other devices is normal, repair or replace the damaged communication line.

The furnace door is not tightly sealed

Reason for malfunction: The sealing strip is aging or damaged.

Solution: Replace the sealing strip to ensure good sealing of the furnace door.

Transistor leakage 

Reason for malfunction: Insulation damage.

Solution: Check the insulation condition of the equipment and use an insulation resistance tester to measure the insulation resistance of the equipment. If insulation damage is found, repair or replace the damaged insulation components.

Display Exception

Reason for malfunction: Display instrument malfunction.

Solution: Replace the display instrument to ensure normal display.