Reasons for choosing an ESE Air Terminal with a good isolation under rain

Reasons for choosing an ESE Air Terminal with a good isolation under rain

Lightning protection systems shall work correctly for many years.  Therefore it is essential to assure the immutability of their components under different environments and extreme conditions.

DAT CONTROLER® PLUS ESE air terminals are subject to severe controls and evaluations.  Thanks to those controls, DAT CONTROLER® PLUS Air Terminals are certificated with the quality mark N of AENOR (the Spanish official organization for standardization) that verifies periodically, on production samples, that all the parameters required by the normative are accomplished.

Four tests are applied to these air terminals for assuring a good performance even in corrosive atmospheres or after receiving a lightning strike:

  1. Salt mist treatment, in a highly corrosive atmosphere (as the one existing in industrial zones, large cities and coastal areas)

Afterwards, the same sample is submitted to:

  1. Sulphurous atmosphere treatment inside a humid sulphur dioxide atmosphere, simulating a high level of industrial pollution (acid rain effect), which is becoming increasingly important in industrial environments and even in mountain areas.

After these tests, the same sample passes:

  1. An electric test, applying 3 current impulses with a peak of 100 kA.
  2. The advance time test, which defines its protection area.

These tests are mandatory for all ESE air terminals according to the applicable standard.

Additionally, Aplicaciones Tecnológicas submits DAT CONTROLER® PLUS Air terminals to a more severe protocol that includes the following tests:

  1. Electric test expanded to 20 current impulses, 100 kA with 10/350 µs wave, significantly increasing and exceeding the Standard requirements that, as pointed above, demand only 3 impulses. Of the 20 impulses, 10 are of positive and 10 of negative polarity, thus checking DAT CONTROLER® PLUS air terminals for all type of lightning events, which may be of different polarity.
  1. Isolation tests under rain. DAT CONTROLER® PLUS air terminals, thanks to a system patented by Aplicaciones Tecnológicas, pass the tests described in the standards with an isolation higher than 95%.


Even though the two phenomena do not always happen at the same time, it is actually quite frequent that lightning is accompanied by rainfall, specially in humid tropical countries and/or with large pluviometry. The working principle of ESE air terminals is based on the existence of an isolated terminal that is charged with the atmospheric field. 

When the case does not guarantee the ESE air terminal internal parts isolation under rain, snow, hail, etc., the internal electronic circuit gets disabled. As a result the air terminal acts as a Franklin rod, lessening the protection radius of the air terminal and thus leaving unprotected the initially covered areas.