Atmospheric and altitude correction factors for air gaps and clean insulators

This Technical Brochure provides an overview of the existing atmospheric and altitude correction methodologies, stipulated in various IEC standards. It outlines the common ideas and differences between atmospheric and altitude corrections including their insufficiencies and inadequacies. The Brochure covers the physical background and includes historical test data on which the current methods are based as well as new test data up to 4200 m.  Separate chapters are dedicated to air density corrections for short gaps, long gaps and humidity corrections for AC, DC, LI and SI. It gives an outlook of possible modifications to the current methodologies of atmospheric and altitude corrections.