Thermal analysis & ovens
Hot Air Oven
An electrically heated, insulated cabinet that holds samples or glassware at a set temperature. In QC it is used mainly for loss on drying, drying of reference materials and drying of glassware.
- Pharmaceutical
- Food & beverage
- Chemicals
- Materials testing
- Education
TROUBLESHOOTING
Common problems, causes and fixes
Oven does not reach set temperature
Likely causes
- • Failed heating element
- • Door seal damaged or door left open
- • Controller fault
What to do
- • Have the element checked and replaced
- • Replace the gasket and close the door properly
- • Service the controller
Temperature overshoots or cycles widely
Likely causes
- • Poorly tuned controller
- • Sensor displaced or faulty
What to do
- • Retune the PID controller
- • Reposition or replace the sensor and recalibrate
Display reading differs from reference thermometer
Likely causes
- • Sensor drift
- • Controller offset not adjusted
What to do
- • Recalibrate and apply the offset as per SOP
- • Replace the sensor if drift is large
Poor uniformity (hot or cold spots)
Likely causes
- • Fan not working
- • Overloaded shelves
- • Blocked vents
What to do
- • Repair the fan
- • Reduce load and space containers
- • Clear the vents and repeat mapping
LOD results variable between analysts
Likely causes
- • Different shelf positions
- • Samples weighed while warm
- • Inconsistent cooling time in the desiccator
What to do
- • Use only mapped positions
- • Cool to room temperature before weighing
- • Fix the cooling time in the method
Over-temperature alarm or cut-out trips
Likely causes
- • Controller failure
- • Cut-out set too close to the working temperature
What to do
- • Stop use and have the controller checked
- • Set the cut-out as per manufacturer guidance
In LimsPulse · Calibration Management
Keep every Hot air oven in control: usage logs, calibration and maintenance schedules, and automatic blocking of overdue instruments.