SignalFire Telemetry System Design Guards Against Lightning Strike Damage
Lightning can be an issue for remote sensor control systems, especially in the upstream oilfield. Sensors located on top of 20 – 24 ft. steel tanks become ideal targets for lightning. One unfortunate strike can take out a sensor or the entire telemetry system.
SignalFire’s wireless telemetry is designed for reliable operation in outdoor applications under various conditions including rain, snow, ice, sun and even lightning. Using a wireless network to connect remote sensors and devices creates a basic “lightning-resistant” system. On the other hand, the configuration of a wired system connects all remote devices to each other and a centrally located controller makes it susceptible to lightning damage. A lightning strike at any one location will, almost certainly, destroy all devices on the network. A wireless system does not have this weakness as devices are not wired together, making it larger immune to lightning strikes.
The SignalFire Remote Sensing System incorporates additional features that simplify lightening protection. While no system can withstand a direct lightning strike, a more problematic issue is imminent or nearby lightening. In these cases, a strong electrical field will affect devices located above ground by subjecting it to a voltage difference between the antenna (up high) and radio (down low).
Many telemetry systems that connect an antenna by coax to a radio use expensive lightening arresters to reduce the chance of this potential difference from harming the input amplifiers of the radio. A SignalFire Gateway Stick (see photo) is uniquely designed with the radio collocated with the antenna in the Stick. The elimination of coax and distance between the antenna and radio amplifiers make them more immune to static and electric field effects.
With any wireless system, higher antenna placement provides for better range. While increasing reception quality, higher antenna positioning makes equipment susceptible to lightening issues as lightening likes things that stick up. SignalFire solves this issue by combining radio electronics and the antenna into an integrated housing that features static dissipating devices within the electronics.
While wireless networks are inherently more resistant to lightening, the Signal Fire Gateway Stick products add extra insurance by co-locating the antenna and electronics into one convenient housing and including protection devices inside the package.