User's Manual

SRT X-BAND RADAR SYSTEMS
ANNEX
304202P003 21 Rev. C
4.4 Pressurisation
After all connections have been completed, pressurise waveguide. Changes in
temperature can cause moisture from outside air that enters waveguide to
condense and seriously impair efficiency, so waveguide must be under
pressure at all times.
If moist air has entered, must be purged. Remove gas port plug located on
connector at Antenna Group end of waveguide, and purge waveguide
continuously until it is dry. After purging, replace gas port plug and pressurise
waveguide.
Dry air is normally used for pressurising. Dry nitrogen may also be used. After
installation, check waveguide connections for leaks. Use commercial leak
detector or liquid detergent over joints and check for bubbles. Un-broken soap
film over entire joint for several minutes will indicate very small leaks.