Dry Air Systems
Figure 1: Compressor-dehydrator of the PAR-80 ATC-radar
Some radars depend on inputs of dry air for proper operation. Microwave components, such as waveguides, cavities, and power amplifiers, require dry air to prevent arcing and internal corrosion. The electronics dry-air branch must satisfy the dry-air requirements of the electronic user equipment. Dry air of less than the required specifications will degrade equipment performance.
Some units of electronic equipment that have local dehydrator units are pressure interlocked within the dehydrator unit. When the outlet air pressure is below a set value, the interlock prevents the equipment from going to a full operate condition.
Figure 2: Desiccant dehydrator
The electronics dry-air branch is fed from the compressor air main through desiccant dehydrators. Desiccant dehydrators are tubes made of steel, filled with granules of crystals which endeavours to include water molecules into its crystal lattice. The compressed air is conducted by such tubes and is dried there.