How to solve the difference between the actual temperature and the measured temperature of a vacuum atmosphere tube furnace?

When the actual temperature of a vacuum tube furnace does not match the measured temperature, the following steps can be taken to solve this problem:
1. Check the measuring equipment
Calibration thermometer: First, confirm whether the thermometer is accurate. Standard thermometers or other reliable temperature measuring devices can be used to calibrate the thermometer to ensure that its measurement accuracy meets the requirements.
Check thermocouple: Thermocouples are commonly used temperature measuring components, and their accuracy and stability are crucial for temperature measurement. Check if the thermocouple is installed properly, positioned correctly, and if there is any damage or aging. If necessary, replace the thermocouple with a new one in a timely manner.
2. Check the control system
Check the temperature controller: The temperature controller is a key component for controlling the temperature inside the furnace. Check if the controller settings are correct, including temperature settings, control modes, etc. At the same time, confirm whether the controller is working properly and there are no fault alarms.
Adjusting control parameters: If there is a significant difference between the actual temperature and the set temperature, you can try adjusting the parameters of the temperature controller, such as proportional coefficient, integration time, differentiation time, etc., to optimize the control effect. However, please note that the adjustment of these parameters needs to be based on specific circumstances and cannot be blindly modified.
3. Check the furnace body and heating elements
Check the sealing of the furnace body: The sealing of the furnace body has a significant impact on vacuum degree and temperature control. Check if the sealing components at the furnace door, observation window, etc. are intact to ensure that the gas inside the furnace does not leak out.
Check the heating element: The performance of the heating element directly affects the uniformity and stability of the temperature inside the furnace. Check whether the heating element is aging, damaged, or has poor contact. If necessary, replace it with a new heating element in a timely manner.
4. Perform multi-point calibration
Calibration using reference materials: Select one or more reference materials and calibrate at multiple temperature points. By measuring the characteristic temperature points such as melting point and boiling point of the reference substance, the accuracy and stability of the furnace temperature can be verified.
Calibration using a temperature measuring ring: The temperature measuring ring can provide the actual accumulated heat based on its linear contraction within its working range, thereby calculating the actual temperature. Place the temperature measuring ring into the furnace and calibrate the temperature inside the furnace based on the diameter change of the temperature measuring ring.
5. Other precautions
Ensure power stability: Fluctuations in power supply voltage can also affect the accuracy of temperature control. Check if the power supply voltage is stable, and if necessary, install a voltage regulator to ensure a stable power supply.
Regular maintenance: Regularly maintain the vacuum atmosphere tube furnace, including cleaning the heater, checking the temperature probe, cleaning the intake pipe, etc., to ensure the normal operation of the equipment and the accuracy of temperature control.
Through the above steps, the problem of inconsistency between the actual temperature and the measured temperature of the vacuum atmosphere tube furnace can be effectively solved. If the problem persists, it is recommended to contact the equipment manufacturer or professional maintenance personnel for further inspection and repair.