Monday, October 25, 2010

Rooftop RF

As I travel around the Washington, D.C., area, I can’t help but notice the tremendous number of buildings that have numerous antennas mounted to the roof. I wonder if anyone has considered the overall RF to which workers that access these roofs could be exposed. Workers such as window washers, elevator mechanics and HVAC service personnel, just to name a few. If the RF situation on the roof has not been measured, the roof of such a building would be considered by the FCC and OSHA to be an uncontrolled environment and a significantly stricter RF exposure standard would apply. As a result, I believe that many of these buildings would not meet the tougher exposure guidelines in certain areas. While the owners of the transmitting antennas would bear the entirety of the FCC’s and OSHA’s fines and mitigation techniques, the building owner would undoubtedly be sucked into any lawsuit brought by a worker that believed that the antenna owner and building were negligent with respect to an RF exposure issue.

A power density study would provide a measure of safety to the building, its workers and the antenna owners. Such a measurement survey would identify areas of the roof that workers should avoid and how the building/antenna owner should mark these areas (usually chained off and RF warning signs attached to the chain). The study also determines the major contributors to the areas of concern so that these antennas can be taken off the air if these areas need to be accessed by workers for maintenance or repair.

Smith and Fisher has state of the art power density meters which can measure total RF levels in any area and can identify the specific major RF contributors in areas of concern.