How do I monitor temperature in refrigerated transport?

When carrying food, medicines or flowers, temperature is not an option but a contractual and sanitary obligation. Proof comes from records, not statements. Below you see what you need and what the customer asks for at reception.

Short answer

A refrigerated vehicle needs a valid ATP certificate attesting the insulation class and the cooling capacity.
You fit sensors inside the cargo compartment, not only at the refrigeration unit.
Continuous temperature recording, the so-called thermograph record, is the proof that the cold chain was kept.
You set alert thresholds per goods type and get a real-time notification on deviation.
You archive the records together with the trip documents, because large retailers ask for them at reception.

What the law says (in brief)

The ATP agreement governs the international carriage of perishable foodstuffs and is signed by Romania.
The ATP certificate is issued per vehicle, with limited validity, and is extended after a technical inspection.
Operators carrying food apply procedures based on HACCP principles, including monitoring and archiving records.
Vehicles intended for products of animal origin need a sanitary-veterinary authorisation.
The digital temperature record is accepted as legal proof that the cold chain was maintained.

Practical example

Example: a dairy shipment required at 2 to 4 degrees Celsius leaves Brasov for a warehouse in Bucharest. The compartment sensor records every 5 minutes. During a long stop the temperature climbs to 6.4 degrees for 18 minutes, the dispatcher gets an alert and asks the driver to start the unit. At reception, the warehouse receives the full record and accepts the goods without argument.

Common mistakes

Relying on the unit display, which shows the temperature at the fan, not at the goods.
Using a single sensor in a long semi-trailer with two compartments.
Not pre-cooling the compartment before loading, so you start off already out of range.
Keeping the door open during multi-drop unloading, with no air curtain or partitioning.
Losing the record after the trip, so you cannot answer a quality complaint.

How 4transports helps

4transports does not read temperature sensors or send alerts; the temperature record comes from the refrigeration unit.
On each trip you note the cargo type, and the CMR stays recorded on the same trip.
You can note the ATP certificate deadline on the vehicle, and refrigeration unit checks as maintenance.