proof charges

Noun

proof charge (plural proof charges)

1. A charge of powder and ball, greater than the service charge, fired in an arm, as a gun or cannon, to test its strength.
   • Thus the proof-shot with proof-charge may in reality be proving the gun less faithfully than its first service-charge and service-shot,—a mode of proof-practice for heavy artillery very different from that imposed for safety on every fowling-piece.1862, Edward Pellew Halsted, The Armstrong Gun. A Rejoinder to the Letter of Sir W. Armstrong, page 37
2. (electrostatics) A small charge used to test or measure the electric field created by other charges.
   • This means that the proof charge will be repelled by the electric field.Moreover, since the proof charge should not interfere with the measurements and assuming that its starting point is infinity (¥), then VB = 0.2021, J. Felipe de Almeida, Maxwell's Equations and the Principles of Electromagnetic Phenomena, pages 3-12