One-sentence answer: Antenna radomes and RRU cavities work outdoors year-round, and the breathing effect caused by day-night temperature differences continuously pushes moisture toward the seams. Radome splice seams, bolt holes and breather valves are the main leakage paths. Using the CTS Sentinel C28WE (C28) leak detector with pressure decay or vacuum decay for large-volume cavity testing is a common method on base station equipment production lines.
Gas inside the radome repeatedly expands and contracts with sunlight and nighttime cooling. The pressure difference between inside and outside drives moisture in and out along the seams. Even if the initial micro-leak is very small, long-term accumulation will introduce considerable moisture.
Fiberglass or plastic radomes are mostly assembled from multiple pieces. Sealing strips and bolt holes form a large number of potential leakage paths, and the quality of manual adhesive application fluctuates greatly.
The radome is large in size with limited rigidity. It is prone to local deformation during plugging and clamping, causing plugging failure and distorted readings.
Sealing locations: radome splice seams and seal strips, bolt holes and inserts, breather valve (waterproof breathable membrane), mating surface between the cavity and the base, cable entry ports.Consequences of leakage: moisture intrusion causes corrosion of internal power amplifiers and filter components, deterioration of VSWR and gain indicators, and degraded coverage performance. In severe cases, components short-circuit and are damaged, requiring tower climbing for replacement. Maintenance costs are far higher than production line testing costs.
The breathing effect itself cannot be eliminated. The correct approach is to ensure reasonable design of the seams and breather valve, and to include the venting path in the criteria during testing. The C28 program can set independent parameters to distinguish the inherent venting flow of the breather valve from real leakage.
Use fixtures to ensure the flatness of the clamping surface and uniform clamping force, avoiding plugging failure caused by local deformation. At the same time, include daily check of the plugging seals in routine maintenance. This is the most common source of systematic error in large-part testing.
Usually the IP rating requirements of IEC 60529 / GB/T 4208 are referenced and converted into internal air tightness limits in combination with operator specifications. The specific criteria are agreed in the technical agreement, and the instrument executes judgment according to the program.
Yes, but two intentions must be distinguished. If the goal is to evaluate the sealing structure other than the breather valve, temporarily plugging it and first calibrating the air tightness of the plugging part itself is a feasible practice. If the goal is to evaluate the true service sealing state of the entire radome, it cannot be plugged, because the controlled venting flow of the breather valve is a design function. After plugging, the leak rate judged neither represents the service state nor conceals the design defects of the venting path itself.
The core of air tightness for antenna radomes and RRU cavities is sufficient stabilization for large volumes, reliable plugging surfaces, and separate definition of the venting path. The CTS C28WE uses dual methods and 32 programs to adapt to multi-model mixed-line testing. Combined with custom clamping fixtures, it forms the front-end guarantee for the outdoor reliability of base station equipment.
WeChat for technical support
PLUS Douyin
