Oven displays cycle around a target; they do not necessarily hold one exact temperature every second. Use an oven-safe thermometer and measure across multiple cycles.
- Place the thermometer near the centre without touching a tray or wall.
- Select a normal bake setting.
- Allow the oven to complete preheat and stabilise.
- Record several readings at consistent intervals.
- Compare the average with the set temperature.
Do not use an infrared surface thermometer as a direct substitute for air-temperature measurement.