How the early streamer emission is measured - ALPS ESE testing

Updated: Aug 18, 2021


The effectiveness of the ESEAT (Early Streamer Emission Air Terminal) is assessed by comparing, in a high voltage laboratory, the emission time of the ascending tracer which it emits with the one an SRAT (Simple Rod Air Terminal) emits. To achieve this, the SRAT and the ESEAT are assessed one after the other under the same electrical and geometrical conditions during laboratory tests that simulate natural discharge capturing start-up conditions (ascending positive tracer).

50 usable impacts will be recorded. (Example of a non-usable impact:

pre-starting of the generator). The standing time between two impacts shall equal 2 minutes. This value should be maintained throughout the tests.

Based on the measurements of the ascending tracer’s emission times taken from an SRAT and an ESEAT, the average emission times Tmoy’SRAT and Tmoy’ESEAT are calculated based on the usable impacts, while respecting the parameters). The standard deviation of the two distributions are also calculated (σSRAT et σESEAT).

Thelighting conductor is an ESEAT if both the following conditions are met:


• ΣESEAT < 0,8 σSRAT

• TPTS - TPDA > 10 μs


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