Improved Formula Accurately Estimates the Expected Number of Lightning Strikes for a Facility; Demonstrates the Effectiveness of DAS Systems

The formula applied to Dissipation Array® Systems (DAS®) demonstrates downward lightning strikes significantly impacted.

(PRWEB) November 2, 2004 -- It may not have the impact of E=mc2, but a team of international scientists studying the branching effects of downward lightning strikes has developed an improved formula for accurately estimating the expected number of lightning strikes to ordinary ground structures (such as low or high-rise industrial facilities), towers, and antennas. Besides predicting the frequency of strikes, this formula provides the first available method for directly comparing lightning protection systems such as lightning rods with the more high- tech Dissipation Array® Systems (DAS®).

Since the first awareness that lightning is an electrical discharge, scientists and engineers have studied thunderstorms and lightning extensively. While centuries of study and new sophisticated instruments have greatly expanded our knowledge, there is still much about these phenomena that is not clearly understood. However, a joint research team of noted international scientists continue to study the affects of lightning in an effort to ultimately provide better protection for residential and commercial facilities.

Dissipation Array Systems (DAS) -- such as those offered by Lightning Eliminators (www.lightningeliminators.com) and Consultants (LEC) -- are systems based on the point discharge" principle or charge transfer and are designed to prevent lightning strikes from even terminating within protected areas.

In the study, scientists were trying to determine what happens when a branch of lightning progresses toward a ground object protected with DAS, prior to other branches reaching the ground surface or some other grounded object.

Although branched downward lightning discharges are a common occurrence, they have rarely been studied in this level of detail because speeds are measured in single digit microseconds. To study this phenomenon, advanced computer simulations were required. Unfortunately, available programs were insufficient and had to be heavily modified by the scientific team to simulate this type of event properly.

With this problem solved, the team turned its attention to another issue. At the time of the research, no reliable method existed to calculate the number of lightning strikes expected to hit an object or facility that took into account the effect of coronae.

The concept of corona space charge is specifically important to the operation of the DAS. DAS is based on a natural phenomenon known to scientists for centuries as the point discharge" principle or charge transfer. A sharp point in a strong electrostatic field will leak off electrons by ionizing the adjacent air molecules, providing the point's potential is raised 10,000 volts above that of its surroundings.

Due to the corona space charge created by DAS, the formation of counter leaders are delayed, prevented long enough to allow other branches of a downward leader to terminate on some other unprotected ground object. As the study demonstrates, after the contact between the downward leader and ground, the lightning channel is neutralized and the object protected with DAS remains undamaged.

With this in mind, the international team of scientists was able to develop the improved formula for estimating the number of lightning strikes to a facility. The formula, which takes into account not only the height of the object, but the shape (an important factor when considering DAS), could then be used to effectively estimate the risk of strikes to the installation with and without the DAS - the first time such a calculation has been made available.

Based on the formula, calculations showed that the installation of DAS on a ground object leads to a considerable reduction in the risk of lightning strikes to a protected site. This conclusion, combined with decades of documented field test data, demonstrates the effectiveness of the DAS system in reducing the risk of a strike to a rate of 99.7% when properly engineered, designed and installed.

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