The experimental packaging unit with the plums was stored in
another temperature-controlled climate chamber BK6160 on a
wire mesh, so that unrestricted free flow around the whole packaging
unit could be guaranteed. The dimensions of the disposable airspace
in the climate chamber were w h d = 60 50 60 cm.
The surrounding air temperature could be adjusted in the range
0–50 C to 0.1 K. Cyclic temperature fluctuations (temperature level
and slope) were set by means of the integrated temperature
control unit Kelvitron-kp (Hereaus Instruments, Hameln, Germany).
A disposable (not adjustable) fan on the rear panel of the
climate chamber was switched on as and when needed and thus
allowed a slightly forced convection (crosswise flow against the
packaging unit). Unrestricted natural convection against and
around the packaging unit was present when the fan was turned
off. The real course of the air temperature, differing from controller
settings, was affected by the dimensions and the installations
(packaging, auxiliary equipments) of the climatic chamber, the airflow
and the efficiency of the chamber’s cooling/heating unit.