A single-use temperature logger is a small sealed device: one battery, one sensor, onboard memory. It rides inside the box, records a reading at a set interval for the length of the trip, and gets read out once at the destination. A real-time logger senses the same data but adds a radio, cellular, satellite, or Bluetooth to a nearby gateway, so every reading leaves the box while the shipment is still moving. Same physical job, different moment when the information becomes useful.
The real choice is not about sensor accuracy. Both formats measure temperature about as well as each other. It is about whether anyone can do anything with the reading before the shipment arrives. A single-use logger produces a record: proof of what happened, read after the fact. A real-time logger produces a live feed: a chance to intervene while the product is still in transit. That difference decides which one earns its cost on a given lane, far more than any spec sheet does.
Recording after the fact vs acting during transit
A single-use logger stores every reading in its own memory and does nothing else with it. Nobody sees the data until someone plugs it into a reader or scans a printed report at the receiving dock, hours or days after an excursion, if there was one, already happened. There is no alert, no dashboard, no way to reach the shipment while it is still moving. The report is a closed file: useful for proving what the product experienced, useless for changing what the product experiences.
A real-time logger adds a transmitter. It reports its readings on an interval, often every few minutes, to a server over a cellular or satellite link, or hands them to a gateway over Bluetooth at each handling point. Cross a temperature threshold and the system pushes an alert immediately, while the shipment is still on a truck, on a tarmac, or in a reefer container. Someone downstream can reroute the load, swap in fresh coolant at the next stop, hold it at a hub, or reject it at handoff, before the product is a loss rather than after.
Cost per shipment
Single-use loggers are cheap enough to throw away. There is no device to retrieve, no subscription, no data plan, and no return logistics: the unit travels with the shipment and gets discarded or recycled at the far end. That economics works at volume, one logger per parcel, thousands of parcels a month, with the cost buried in packaging spend. A real-time unit costs many times more to build, and the price does not stop at the hardware. Airtime, a data plan and platform access are usually billed per trip or per month, and the device is meant to be reused, which means someone has to get it back. Skip the retrieval step and the second cost erases the first shipment's savings.
The record is enough
Most 2-8°C parcel shipments do not need a live feed. A short regional lane, a product with a forgiving hold time, a shipment protected by gel packs or a phase change material sized with margin, and a receiving process that only needs proof of compliance for release paperwork: all of that is satisfied by a report read after arrival. Nobody downstream was going to act on a mid-transit alert anyway, because the lane is short enough that by the time anyone read it, the truck would already be at the dock.
Cargo that justifies live tracking
A long or multi-leg lane changes the calculation: international air freight with a customs hold, an ocean reefer container crossing with several transfers, or any air cargo routing with a tight connection. So does cargo that cannot be replaced: a single clinical trial batch, a cell or gene therapy shipment, a vaccine lot with no second batch waiting. On those lanes the dwell time between handoffs is long enough that an alert can still reach someone before the product is lost, and the value at risk justifies paying to find out early.
Matching the device to the lane
Neither format wins on its own. A cheap, high-volume domestic lane rarely justifies live tracking: the subscription and retrieval cost swamps the value of an alert nobody needed. A single irreplaceable shipment on a long, multi-leg route rarely justifies going without it: the cost of a live feed is trivial next to the cost of a lost batch. Choose by shipment value, leg count, and whether the receiving process can act on a temperature data logger reading before the truck arrives, not by which device looks more capable on a spec sheet. Real-time temperature monitoring earns its cost on the lanes where someone can still do something.