For harsh environments, connector design and selection are critical
The importance of delivering connector reliability in harsh environments
In the world of engineering, connectors are the unsung heroes that ensure the seamless operation of complex systems. For harsh environments, connector design and selection are critical. Delivering long-term reliable connector performance will involve mitigating one or multiple risks posed by the operational environment, such as environmental temperature, vibration and shock, exposure to water and dirt, access restrictions, and hazardous or corrosive substances connectors might be exposed to.
TOLERATING TEMPERATURE CHANGES
Connectors for outdoor telecom equipment need to withstand exposure to the elements while maintaining high data transmission rates. Components must be manufactured from suitable materials to tolerate temperature extremes yet not suffer cracking or damage. Changes in temperature can cause connector and cable materials to expand and contract, affecting connector performance through loss or degradation of signal. However, clever connector design can overcome some of these challenges.
Anti-piston or anti-rifling connectors with a 2-part contact design (such as the one in figure A) allow the centre conductor to slide within the connector, where expansion and contraction of the cable centre conductor due to temperature changes is found. In this example, a white bronze connector body in place of the normal nickel body plating of a TNC offers enhanced corrosion resistance.
AVOIDING DAMAGE FROM DIRT
Connectors for use on agricultural equipment will be regularly subjected to liquid and/or dust which could damage equipment and negatively impact the RF signal. Selecting a connector or adaptor with an appropriate Ingress Protection (IP) rating is critical. An IP67 rating provides dust-tight protection against the ingress of solid contaminants for two to eight hours of continual exposure and protection against water ingress when immersed in depths of 15cm to 1m for up to 30 minutes, whereas IP68 provides the same protection from solids, but protects against long-term immersion up to specified depths and water pressures.
VIBRATION PROTECTION
Environmental shock and vibration can negatively affect signal transmission quality by causing connectors to come loose, or even disconnect, resulting in partial to total signal loss. Secure locking mechanisms, like threaded and bayonet options, provide positive mating and a constant signal path. BNC, TNC, SMA, and N-Type RF connector variants feature a silicone gasket that helps protect the locking mechanism against vibration, making them more suitable for industrial applications than push-fit designs which are more likely to spin during vibration, resulting in reduced performance.
RF connectors made with stronger base materials, such as stainless steel, generally permit rougher handling without the risk of reduced performance. Pictured above (top right) is an SMA adaptor made from stainless steel permitting a tighter torque and featuring a silicone gasket to protect the locking mechanism against vibration.
CONNECTOR DESIGN
Reputable connector manufacturers will be able to provide in depth technical information and specifications for each of their products and will be knowledgeable about how to overcome the design challenges that harsh environments may present. Armed with the information customers provide, they will be able suggest off-the-shelf connector or cable assembly suitability. Where a bespoke solution is required, they will be able to work with customers from initial design concepts to the supply of a fully qualified production part.
Emma Ashton is with COAX Connectors.
