Placement mistakes
| Mistake | Why it matters | How to do it right |
|---|---|---|
| A logger on a metal rack without insulation | the sensor shows the temperature of the metal, not of the air near the product | fix it with an insulating pad; the sensor must not touch metal or concrete |
| Points only at eye level | top levels are often 2–4 °C warmer in hot weather — the hot spot is missed | vertically: the bottom logger at the bottom storage level, the top one at the top level |
| No points at gates, air conditioners, heaters | risk zones are not studied | add risk points to the EEC grid |
| No outdoor logger | it is unclear how hot or cold the period was | one logger outside the area if it borders the outdoors or an unheated room |
| Loggers moved by a forklift | the point data no longer match the layout | fix them so they do not interfere with work; brief the staff |
Method mistakes
| Mistake | Why it matters | How to do it right |
|---|---|---|
| Different logger models | differences in time constant and accuracy look like “hot spots” | loggers of one type |
| Loggers without verification or calibration | results cannot be presented | valid verification, recorded in the report; accuracy within ±0.5 °C |
| Three days instead of a week | weekends and the climate system cycle are missed | a warehouse — at least 7 consecutive days; a chamber — 24–72 hours |
| Recording interval too long | gate openings and compressor cycles are not visible | an interval of 1 to 15 minutes, usually 5–10 for a warehouse |
| Loggers started at different times | points cannot be compared in time | the same interval and a synchronised start |
| One study for all seasons | the winter gate problem is invisible in summer, and vice versa | initial mapping — summer and winter; re-mapping — in the critical season |
| The warehouse was “prepared” for the study | the A/C turned up, gates kept closed — data do not reflect operation | work as usual and record unusual events |
Mistakes in and after the report
| Mistake | Why it matters | How to do it right |
|---|---|---|
| A report without decisions | there are charts but no actions | a suitability conclusion, places where storage is not allowed, monitoring points, corrective actions |
| Monitoring sensors not moved | monitoring is done at points other than those found by mapping | under Rules 260n, item 18, wholesalers place monitoring devices based on mapping |
| The layout was not kept | the next study cannot be compared with the previous one | point numbers and the layout are part of the protocol and report |
| Not repeated after changes | re-planning or a new air conditioner changed the picture | re-mapping after changes and based on risk assessment |
Cold room mistakes
- Product right against the evaporator — a freezing risk. Leave a gap between product and walls and free air flow under the ceiling.
- The unit's control sensor passed off as a monitoring sensor. These are different devices with different tasks: the monitoring sensor is placed based on mapping, most often at the warmest point with product.
- No power-off test. Without it you do not know how many minutes the chamber holds its range — the basis of the emergency plan.
You can check whether re-mapping is needed after changes with the hint on the re-mapping page, and prepare for a study with the readiness checklist.
Frequently asked questions
Why must loggers be of one type?
Different models have different time constants and accuracy. The difference between them looks like a temperature difference between points — and the report shows “hot spots” that do not exist.
Why can't mapping take three days?
A week is needed to capture working days with gate openings, nights and weekends when ventilation and heating behave differently. For a warehouse the EEC Guideline provides for at least 7 days.
What if a logger was moved during the study?
Record when and what happened and tell the contractor. The data for that point are assessed separately; if the point is critical, the study is extended or repeated.