This acrylic cabinet is customized for storage of polycarbonate
films used for high-precision screening of circuit boards.
It maintains critical relative humidity and temperature levels
to prevent dimensional aberrations that result from exposure
to humidity and temperature fluctuations.
± 3%RH within ± 20% of ambient
± 2°F (-18.9°C to -16.7°C) within ± 10°F (-23.3°C to -12.2°C) of ambient
Air circulates horizontally across the shelves that hold
the film. As air exits the storage area, it passes through
an air conditioning/heating module that conditions it to within
±2°F (-18.9°C to -16.7°C) of the temperature set point. In addition,
the continuously operating A/C module removes moisture to
keep the %RH level within ±3% of the set point. If
humidity falls too low, an ultrasonic humidifier cycles on
to add the proper amount of water vapor. If the temperature
falls too low, the heater module cycles on. A water filtration
system removes contaminants from the humidification feed water
to eliminate the chance of mineral deposits or other vapor-borne
As the process air exits the RH/temperature modules, an
impeller blower draws it into an intake plenum area and forces
it uniformly back through the storage area.