Cold Chain Refrigerated Transport Monitoring, TG Tracking

Refrigerated Transport Temperature Monitoring

A reefer trailer pulls out of a Cape Town packhouse at 03:00 with 22 pallets of late-season citrus on a four-day run to the Durban port and a vessel sailing for Rotterdam on Wednesday afternoon. Somewhere on the long climb between Beaufort West and Three Sisters the compressor short-cycles, runs four minutes on, six off, and the rear-door zone drifts up by 4 degrees before the driver notices at the next refuel. The buyer at the other end will reject any pallet outside spec. The difference between a delivered load and a write-off is the alert that fires inside that gap, plus a log that proves every other hour of the trip held inside the spec window.

Direct answer

Refrigerated transport temperature monitoring from TG Tracking covers reefer trailers, refrigerated trucks and refrigerated vans on long-haul, regional and last-mile routes. Multi-zone in-transit probes, door sensors, compressor power-loss alerts and route-linked audit logs run on the same platform as your Trailer Management and Fleet Tracking and Management, and feed into the parent pillar Temperature and Cold Chain Monitoring for cross-application reporting.

What goes wrong inside a moving reefer

A reefer is a pressurised micro-climate moving at 90 km/h. Three things go wrong, often in combination, and a temperature gauge alone catches none in time.

Compressor short-cycle on idle or hill descent. The unit cycles too fast, the cold air does not redistribute, and the rear zone drifts before the front-zone gauge shows it. A multi-zone probe with 5-minute reporting catches the divergence early.

Door-open events at customer drops. Multi-stop loads spend time with the back door open while a forklift swings pallets out. A 3-minute door-open threshold turns long stops into an alert before the cold air is gone.

Power loss on idle or coupling change. A tractor change at a yard, a fault on the diesel circuit, each one cuts cooling. A power-state sensor distinguishes a planned defrost from an unplanned stop.

Building an audit trail that survives a customer dispute

The temperature reading is the easy part. The hard part is producing a record, weeks later, that satisfies an EU buyer, a SAHPRA inspector or an insurer that cargo held spec for the trip.

The platform writes a continuous, time-stamped log per zone, with GPS, door state and power state on the same timeline. When a customer queries a load, the export is one PDF with the curve, the deviation, the cause and the recovery. A SAHPRA-style audit window is a 10-second filter.

The integrated record also holds together an insurance claim. Without an in-transit log, the claim depends on goodwill. With a curve, a door-open log and a power-state event tied to GPS, it has evidence behind it.

South African corridors that put cold chains under pressure

South African reefer routes have specific stress points. The Cape Town to Durban citrus run hits N1 passes where ambient temperature swings 20 degrees inside an hour. The Joburg to Cape Town meat loop goes through Karoo heat that pushes any compressor to its duty-cycle limit. Cross-border runs into Maputo and Beit Bridge hit border-post dwell times where a reefer sits idling in 35-degree heat.

Multi-network connectivity carries the in-transit feed across corridors where one network drops. Where signal is weak, the device caches readings locally and uploads when coverage returns.

For reefer trailers without constant power during depot stays, Wireless asset tracking hardware sits inside the same platform. For conditions at the depots and packhouses, see Environmental sensor monitoring and the parent Remote sensor monitoring page. The cold-chain story lives at Temperature and Cold Chain Monitoring, with the broader view at Business solutions.

Frequently asked questions

Protect every load from depot to dock

If your cargo is rejected at spec, the in-transit record is what stands between a delivered load and a write-off.