What we have written on the cold chain100 / 154

There is no universal top-or-bottom rule. Check rails, clearances and sensor map against model instructions.

Colour or appearance alone is not enough. Match plate code and phase-change data to the intended product.

Measure rounds, load, usable space and delivery windows to test whether another vehicle is needed.

Cold air sinks, warmed air rises, corners sit closer to the outside and every lid opening upsets the balance. One reading cannot describe the whole container; the worst point is found by mapping.

Wind can increase heat exchange between a surface and its surroundings; the direction depends on conditions. Separate surface and product readings.

Shows how much extra heat humid air brings into the box at each lid opening, how many grams of ice that equals, and how to choose the plate's melting point.

Do not assume lid effects; inspect and record the gasket, closure, openings and body together.

Do not assume a linear link between insulation thickness and hold time; measure the assembled model.

Assess condensation with dew-point and surface measurements; sweating alone does not prove an insulation defect.

Compare your service conditions and records, not just a competitor's price. Results are not equivalent when product, route or monitoring differs.

Define model, load and test conditions instead of a single temperature promise; specify handover measurement and responsibility.

Check the model, load and conditions in the test report, then trial the same setup with sensors on your route.