Common faults and solutions of vacuum graphite furnace

During long-term use, vacuum graphite furnaces may encounter some common malfunctions. Here are some common faults and their solutions:

1. Power failure
Fault phenomenon: The device cannot start or runs unstably.
resolvent:
Check if the power lines and switches are functioning properly to ensure a stable power supply.
Check if the fuse of the equipment is blown, and replace it with a new one if necessary.

2. Temperature controller malfunction
Fault phenomenon: Inaccurate temperature control, unable to achieve the expected temperature or excessive temperature fluctuations.
resolvent:
Use a multimeter to check if the resistance value of the thermostat is normal.
Check if the setting parameters of the thermostat are correct, and try resetting or calibrating the thermostat.
If the thermostat is damaged, it needs to be replaced with a new one.
3. Heating element damaged
Fault phenomenon: The heating effect is weakened or unable to heat up.
resolvent:
Use a multimeter to check if the resistance value of the heating element is normal.
If the heating element is damaged, it is necessary to replace it with a new one in a timely manner and ensure correct installation.

4. Insufficient vacuum degree
Fault phenomenon: The vacuum pump cannot achieve the expected vacuum degree.
resolvent:
Check the operating status and sound of the vacuum pump for normal operation. If there are any abnormalities, repair or replacement is required.
Check the oil level and quality of the vacuum pump to ensure that the oil level is normal and the oil quality is good. If the oil quality is poor, a new vacuum pump oil needs to be replaced.
Check if the seals are aging or damaged, and replace them with new ones if necessary.
Check if the pipeline is unobstructed. If there is any blockage, clean the pipeline and filter.

5. Furnace body leakage
Fault phenomenon: The furnace body is not tightly sealed, resulting in a decrease in vacuum degree.
resolvent:
Use soap water or a leak detector to conduct a leak test on the furnace body, with a focus on inspecting the sealing surface and flange connections.
If a leakage point is found, it is necessary to fill the sealing gap with sealant or replace it with a new gasket or sealing ring.

6. Motor malfunction
Fault phenomenon: The motor runs unstably or cannot start.
resolvent:
Observe the operation status and sound of the motor to see if it is normal.
Check if the transmission components of the motor are worn or broken, and replace them with new ones if necessary.
If the motor is severely damaged, a new motor needs to be replaced.

7. Other faults
Injection needle issue:
Sample liquid escaping from graphite tube: It may be due to water hanging on the injection needle or the injection needle being biased towards one side of the graphite tube. Simply wipe the injection needle with anhydrous ethanol a few times and adjust the position of the injection needle and graphite tube.
The injection needle cannot extract the sample solution normally: it may be due to bubbles in the syringe. After pulling out the plunger and pushing the tube of the syringe, perform cleaning operations in the software until all bubbles are expelled.
The injection needle cannot enter the graphite tube normally: it may be due to displacement caused by prolonged operation of the injector or bending of the injection needle. The position of the injection needle and the graphite tube can be adjusted or replaced.
Graphite tube issue:
The short lifespan of graphite tubes may be due to incomplete digestion of the sample solution, resulting in organic matter accumulating on the tube wall and deteriorating the performance of the graphite furnace. Therefore, the digestion process needs to be optimized.
Signal drift: It may be due to poor preheating of the hollow cathode lamp or deterioration or damage of the graphite tube, requiring preheating of the hollow cathode lamp or replacement of the graphite tube.
Poor linear fitting of the elemental working curve: It may be due to the frequent use of graphite tubes, resulting in decreased sensitivity and stability, and requiring replacement with new graphite tubes.

In summary, common faults of vacuum graphite furnaces involve multiple aspects such as power supply, temperature controller, heating element, vacuum degree, furnace body sealing, and motor. When solving these faults, it is necessary to carefully inspect the various components of the equipment and adopt corresponding solutions according to the specific situation. Meanwhile, strengthening preventive maintenance and daily upkeep of equipment is also an important measure to reduce the occurrence of malfunctions.