Common faults and solutions of experimental gradient tube furnace

The experimental gradient tube furnace may encounter some common faults during use. The following are some common faults and their solutions:

1. Power supply and display malfunction
Fault phenomenon: After the tube furnace is powered on, there is no power display on the instrument.
Possible reason: The plug is not properly inserted; The fuse is blown; The fuse of the control circuit is blown.
Solution: Check if the plug is plugged in or connected properly; Replace the fuse; Check for any short circuits and replace the fuse after troubleshooting.
Fault phenomenon: The instrument SV alternately displays “ORAL”.
Possible cause: Short circuit of thermocouple.
Solution: Replace the thermocouple.
Fault phenomenon: The instrument SV alternately displays “HIAL”.
Possible reason: The temperature inside the furnace exceeded the limit, and the instrument acted as a protective measure.
Solution: Wait until the temperature drops to a safe level before the instrument returns to normal.

2. Heating and temperature control malfunction
Fault phenomenon: The power supply and heating elements of the tube furnace are normal, but the temperature inside the furnace does not rise.
Possible reason: The set temperature is relatively low; The control circuit is damaged.
Solution: Adjust the set temperature; Notify professional maintenance personnel to inspect and control the circuit.
Fault phenomenon: The set temperature does not match the temperature inside the furnace, resulting in a positive or negative deviation.
Possible reasons: Damage to temperature sensor or temperature controller; There is a deviation between the temperature measurement point and the layout point.
Solution: Replace the temperature sensor or thermostat; Set up the layout position to ensure accurate temperature measurement.
Fault phenomenon: The tube furnace instrument is outputting normally, but the OUT indicator light is not flashing.
Possible cause: The main circuit has malfunctioned.
Solution: Check if the heating resistor wire is open circuited; Check if the thyristor is damaged; If there is heating, check and replace the indicator light.

3. Furnace and seal failure
Fault phenomenon: Uneven temperature distribution inside the furnace leads to abnormal temperature display.
Possible reasons: There may be dirt inside the furnace or uneven distribution of heating elements.
Solution: Clean the tube furnace and remove the dirt inside the furnace; Check the distribution of heating elements and make necessary adjustments to ensure even temperature distribution.
Fault phenomenon: Severe temperature loss and abnormal temperature display inside the tube furnace.
Possible cause: Damaged or improperly installed furnace door seals.
Solution: Check if the furnace door seal is damaged. If it is damaged, replace it with a new seal in a timely manner; Ensure that the furnace door is correctly installed and tightly closed.

4. Other faults
Fault phenomenon: The tube furnace cannot be started or the temperature display is abnormal.
Possible reasons: unstable power supply or malfunction.
Solution: Use a voltmeter to check if the power supply voltage is stable. If it is unstable, replace the stable power supply in a timely manner.
Fault phenomenon: After using the tube furnace for a period of time, the vacuum degree decreases.
Possible reasons: Aging or damage of the heat-resistant silicone ring between the stainless steel flanges; The vacuum system has malfunctioned.
Solution: Replace the heat-resistant silicone ring between the stainless steel flanges; Reinstall the stainless steel flange or replace and repair the vacuum system.

In summary, common faults of experimental gradient tube furnaces mainly include power and display failures, heating and temperature control failures, furnace and sealing failures, and other faults. For these faults, corresponding solutions can be taken according to the specific situation for troubleshooting and repair. Meanwhile, in daily use, it is also important to regularly maintain and upkeep the tube furnace to ensure its normal operation and extend its service life.