Reefer monitoring

Reefer monitoring is the remote tracking of a refrigerated container’s set point, return-air and supply-air temperatures, defrost cycles, alarms, and (on controlled-atmosphere units) oxygen and carbon dioxide levels during transit. Modern reefers carry a telematics modem or a clip-on data logger that reports over cellular and satellite links, so the cold chain is auditable end to end rather than only at plug-in checks. Operators set alarm thresholds against the cargo’s protocol; a deviation flags a remedy before the cargo spoils. The data also supports claims handling, since a temperature record shows whether a breach occurred under the carrier’s control or before stuffing.