Corrosion Resistance for Antennas, Antenna Cables and Connectors: Salt Spray Test

The salt spray test, also known as a salt fog test, is a standardized method used extensively in the industry to evaluate the corrosion resistance of various materials and surface coatings. For antennas, antenna connectors, and cables to be installed in sea-coast areas, this test is particularly important to determine the longevity of the components. 

N-Type connectors are the most corrosion-resistant antenna connector type, because the outer-body is plated with nickel, which is the best plating alloy to resist rust and corrosion.  Nickel-Plated Brass is better than gold-plated brass, for long-term outdoor exposure.

• Our standard nickel-plated connectors can resist 70 hours in a salt spray test without any corrosion-defect.
• Our coaxial cables for antenna cable assemblies can resist 120 hours in a salt spray test without any corrosion-defect:  This applies for LMR-100-equivalnet, LMR-200 equivalent, and LMR-400 equivalent coax types.
• For corrosion-resistance of 120 hours in a salt spray test: We have to customize the connector. This adds an additional 4 weeks delivery time and the product cost will be 20% higher than the standard cable assembly.

Here's how the salt spray test is typically conducted for these components:

1. Test Setup:
   • The components (antennas, connectors, and cables) are placed in a closed testing chamber.
   • A salt solution, usually 5% sodium chloride (NaCl) dissolved in water, is prepared. The pH of this solution is typically adjusted to be within the range of 6.5 to 7.2.
2. Spray Method:
   • The salt solution is atomized using a nozzle to create a fine mist or fog within the chamber. This ensures that the solution is evenly distributed over the test specimens.
3. Exposure Period:
   • The duration of exposure can vary depending on the test standard being followed, but typically ranges from a few hours to several days. Common standards such as ASTM B117 or ISO 9227 specify different durations and conditions based on the expected environmental exposure of the product.
4. Conditions:
   • The temperature within the chamber is maintained at 35°C (95°F) to accelerate the corrosion process.
   • The specimens are periodically inspected to assess the development of rust or corrosion marks.
5. Evaluation:
   • After the exposure period, the components are removed and evaluated for signs of corrosion, such as rust, pitting, or changes in electrical properties (important for antennas and cables).
   • The degree of corrosion is documented, often with photographs, and used to determine whether the component meets the required corrosion resistance standards.
6. Standards:
   • Different standards may apply depending on the specific application of the antenna or cable. Military and marine applications, for example, might require adherence to more stringent standards due to their harsher operating environments.

The salt spray test helps antenna manufacturers to ensure that their products can can maintain functionality and longevity in corrosive coastal environments.