Lightning Protection and Prevention

Method of detection :

AMEO340 is a thunderstorm detection unit, based on the physical principal of measurement and analysis of the electric field at ground level.  This parameter is considered by mainstream scientists as the most representative of situations at risk due to the presence of a thunderstorm cell.  In most cases, thunderstorm cell evolution is predictable and has several known phases: approach, development, maturity and extinction of the thunderstorm cell(s).  The electrical field generated by a thunderstorm is therefore going to continually change, in transitional stages, with either slow or rapid changes in polarity.  These rapid transitional stages are often associated with intra-cloud,  inter-cloud, or cloud to ground lightning discharges.  AMEO340 identifies these stages, which enables it to give pertinent information on the thunderstorm cell development.  Its overall detection ability covers a circle with a radius of 15 km, centered at the unit.  In built-up urban areas, atmospheric pollution is often important; in these conditions, the electric field values are undervalued, preventing them from reaching the threshold required to set off the alarm.
The measurement is done with a rotating electrometer, known as the 'MAC'.  Two electrodes are placed beside each other, one of them mobile and connected to an electric motor, the other fixed and called active.  The mobile electrode acts as a rotating shutter, allowing the active electrode to be cyclicly blocked.  The active electrode is subject to the ambient electric field, which is cancelled out by the passage of the moving electrode.  The obtained result is a periodic signal which is proportional to the atmospheric electric field.  
After filtering and processing the signal, AMEO340 has a rapid response time, which enables it to observe the rapid electric field variations inherent in lightning.

Function of the unit :

The AMEO340 unit is composed of an electrical field measuring probe and a functional loading unit.  The measuring probe has a pick up intelligence that gives it an autonomous function, independent of the loading unit.  Its regular electronic monitoring can be carried out by industrial means, or by remote supervision for the purpose of creating a 'MAC' network.
The 'MAC' contains an interface series, which communicates with the  'ModBus RTU' Protocol, making it accessible to a number of automatic functions and API.
Having said that, the measuring probe can be coupled to its loading unit, which makes it completely autonomous.  Equipped with a human and machine interface, a keyboard and screen, it allows one to see the electrical field values instantaneously, and easily access the pop-up menu, in order to adjust the central loading unit parameters(thresholds, delays, coefficients, etc...)
The loading unit also has five warning lights, of which three are for indicating exceeding the threshold, one for indicating 'voltage present', and one for 'unit malfunction'.  The delivery of this information is done by a relay switch, with no harmful voltage, connected to the unit's status, with a series connection, similar to that of the measurement probe.
Lastly, the loading unit has an internal memory which memorizes the events connected to the status of the unit.
Alternatively, it can be supplied with a housing, connected to the loading unit by fiber optics, for measuring power surges in electric cables.

Installation of the unit:

The 'MAC' is installed outside, preferably far from any obstacles that could hinder its function or render the signal unusable.  The ideal location is at ground level and far from any high objects.
In most cases, due to practical reasons, the 'MAC' is installed on the top of a building; this set-up yields some deformations of the electrical field, which are compensated for by ad hoc adjustments of the unit.

As previously stated, the physical principal of an electric field is the most pertinent and the most representative of the life of a thunderstorm. To be correctly used, it requires both a solid understanding of what causes lightning, and experience in this field, which INEO P&C has.