Monitor a reefer in three ways: the unit's own temperature log, an independent data logger packed with the cargo, and remote monitoring where the shipping line offers it. Add core temperature checks of the product at loading and on arrival.
Each source tells you something different. Together they show whether the cargo stayed frozen and, if not, where the problem happened.
The reefer unit's log
Every modern reefer controller records supply air, return air and set point at regular intervals, along with alarms and power-off events. The shipping line or a surveyor can download this log. It is the first thing to ask for if something goes wrong.
The unit measures air, not product. Air can be at the set point while the core of a warm carton is still above it. That is why the other checks matter.
Independent data loggers
A data logger is a small device that records temperature at set intervals. Many single-use loggers produce a PDF report when plugged into a computer, so no special software is needed. Place them where they reflect the cargo, not the cold air stream.
- Place at least one logger near the door end and one in the middle of the load.
- Put loggers inside a carton or between cartons, not on the floor or the wall.
- Start the logger before loading and note its serial number in the loading report.
- Mark the carton holding the logger so the receiver can find it.
- Download the data on arrival before the cargo is moved to a store.
Remote monitoring
Many shipping lines offer remote container monitoring, which sends unit data over mobile or satellite links. You may see temperature, set point, alarms and power status during the voyage. Ask your forwarder whether it is available on your service and whether you can get access.
Remote data lets you act early. If a unit fails at a transhipment port, the line may be able to repair it or move the cargo before it thaws.
Checks at both ends
If readings are out of range, stop, photograph and call your insurer or a surveyor before unloading further. What to check when the container arrives gives a general list, and what happens if the cold chain breaks covers next steps.
- At loading: probe the core temperature of several cartons and record the readings with photos.
- At loading: confirm the set point, vent setting and power connection.
- On arrival: record the unit display and download the log before opening.
- On arrival: probe cartons from the door, middle and front of the load.
- On arrival: look for frost, ice, soft cartons or clumped product.
Where we come in
We place and log data loggers during loading, record core temperatures with a calibrated probe, and send you the readings and photos with the seal number. If there is a temperature claim later, that record supports it. Start with a free sourcing review.