A single highest value gives the outcome; the slope shows the cause. Divide the difference between two consecutive readings by the minutes between them to get °C/min: a sensor climbing from 3.0 °C to 4.5 °C in 5 minutes warms at 0.3 °C per minute.
- Sync the logger clock with the door, loading and handover records.
- Divide each pair's difference by its duration and match the three fastest sections to the operation records.
- Repeat the calculation on comparable trips.
A short, sharp rise that lines up with one handling step is caused by it: hot air entering when the door opens hits the sensor at once. A low slope that persists along the whole route points to starting temperature, insulation, load pattern and route duration.
A sensor measuring air reacts much faster than one buried in the product, so compare only trips where the sensor sat in the same place. Product decisions rest on the product temperature measurement.
