1Multi functional constant temperature oil bath potBasic principles of troubleshooting
Safety priority: Cut off the power before troubleshooting and wait for the oil temperature to drop to room temperature (≤ 50 ℃) before operation to avoid electric shock or burns;
Simplify first and then complex: prioritize checking basic issues such as external connections and parameter settings, and gradually investigate internal components (such as heating tubes and sensors);
Record traceability: Record the operating conditions at the time of the fault occurrence (such as set temperature, operating time, load conditions), in order to locate and reproduce the problem.
2、 Common troubleshooting solutions
（1） Abnormal temperature control: large deviation between actual temperature and set temperature/temperature fluctuation beyond the range
Troubleshooting steps:
Step 1: Check if the temperature sensor (such as a platinum resistor) is loose, displaced, or if there is oil contamination on the surface (affecting temperature measurement accuracy);
Step 2: Confirm whether the temperature controller parameters are set incorrectly (such as "PID parameters" being tampered with, or "temperature compensation" not being turned on);
Step 3: Observe whether the heating tube is not heating locally (determine if there is any damage to the heating tube);
Step 4: Check if the oil in the oil bath is sufficient (insufficient oil can cause uneven temperature conduction and increased fluctuations).
Solution:
Sensor issue: Re fix the sensor and clean the surface oil stains with anhydrous ethanol; If the sensor is damaged, replace it with a platinum resistor of the same model (such as PT100);
Parameter issue: Restore the factory settings of the temperature controller and recalibrate the PID parameters (refer to the manual, generally set the heating rate to 5-10 ℃/min);
Heating tube issue: Replace damaged heating tubes (pay attention to matching power, such as 1kW/220V);
Oil level issue: Supplement specialized heat transfer oil (such as 320 # high-temperature heat transfer oil) to ensure that the oil level is between the "lowest highest" scale lines.
（2） Heating malfunction: unable to raise temperature/slow heating rate
Troubleshooting steps:
Step 1: Check if the power lines (plugs, sockets, power cords) have poor contact or if the circuit breaker has tripped;
Step 2: Use a multimeter to check the resistance at both ends of the heating tube (the normal resistance value is usually several tens of ohms, if it is infinite, the heating tube will break);
Step 3: Check if the thermostat is in "standby" mode or if the set temperature is lower than the current oil temperature;
Step 4: Check if the insulation layer of the oil bath pot is damaged (insulation failure can cause heat loss and slow heating).
Solution:
Power issue: Re plug and unplug the power supply, replace the damaged power cord; If the circuit breaker trips, investigate whether the overload is caused by a short circuit in the heating tube, repair it, and then close it again;
Heating tube issue: Replace the heating tube with the same specification and ensure that the sealing gasket is intact during installation (to prevent oil leakage);
Mode issue: Switch the thermostat to "Run" mode and reset the target temperature;
Insulation issue: Repair damaged insulation layer (such as replacing rock wool insulation), or wrap insulation cloth around the outer wall.
（3） Operation malfunction: Mixing does not work/excessive noise
Troubleshooting steps:
Step 1: Check if the power cord of the mixing motor is loose or if the motor switch is not turned on;
Step 2: Observe whether the stirring blade is stuck by foreign objects (such as falling sample container fragments), or if the stirring blade collides with the pot body;
Step 3: Rotate the stirring blade by hand to determine if there is any jamming (if it is, it may be due to worn motor bearings or insufficient lubrication).
Solution:
Power/switch issue: Reconnect the motor circuit and turn on the mixing switch;
Foreign object jamming: After cutting off the power, remove the foreign object and adjust the position of the stirring blade (ensuring a gap of ≥ 5mm with the pot body);
Bearing issues: Disassemble the motor, replace worn bearings (such as model 608), or add high-temperature resistant grease (such as lithium based grease).
（4） Oil leakage fault: Oil leakage at the pot body or interface
Troubleshooting steps:
Step 1: Check if the welding seam of the pot body is cracked (commonly caused by aging after long-term high-temperature use);
Step 2: Check if the sealing gasket (such as silicone gasket) of the inlet and outlet oil interface is deformed, aged, or if the interface bolts are not tightened;
Step 3: Confirm whether the sealing gasket of the heating tube installation hole is damaged.
Solution:
Weld cracking: Stop using and contact the manufacturer to repair the weld (such as argon arc welding). After repair, pressure testing is required;
Interface sealing issue: Replace the aging gasket and tighten the interface bolts evenly with a wrench (to avoid damaging the threads due to excessive force);
Sealing issue of heating tube: Replace the sealing gasket of the heating tube installation hole to ensure that the gasket is completely attached during installation.
IIIMulti functional constant temperature oil bath potVerification after troubleshooting
No load test: After troubleshooting, run without load for 30 minutes (set temperature of 80 ℃), observe the temperature stability and stirring operation status, and confirm that there are no abnormalities;
Load testing: Add a standard load (such as a beaker filled with water) and run it for 1 hour according to actual operating conditions to verify temperature control accuracy (deviation should be ≤± 1 ℃), no oil leakage, and no noise;
Regular maintenance: It is recommended to clean the temperature sensor, check the heating tube and seals every month, and replace the heat transfer oil every quarter (to avoid oil aging affecting heat transfer).