These tests are above all used to test components or equipment employed in electricity or electro-technology of medium and high power (circuit-breakers, switches, transformers, insulators, etc...).

For example, oil and air circuit breakers are now replaced by gas ones.

Under a new system of "circuit breakers" for individual stocks put in last month by the SEC, U.S. stock exchanges must briefly halt trading of major stocks that mark big swings.