proof charge

English

Noun

proof charge (plural proof charges)

(firearms) A charge of powder and ball, greater than the service charge, fired in an arm, as a gun or cannon, to test its strength.
- 1862, Edward Pellew Halsted, The Armstrong Gun. A Rejoinder to the Letter of Sir W. Armstrong, page 37:
  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.
- 1872, Francis Sadleir Stoney, Charles Jones, A Text-book of the Construction and Manufacture of the Rifled Ordnance in the British Service, page 112:
  The late Ordnance Select Committee therefore, after having obtained particulars of proof of guns in nearly all theother countries in Europe, came to the conclusion that the proof should be based on the highest charge which the gun will fire on service, and recommended the following proof which was approved in July 1864 and remains still in force, viz., two rounds of 1 1/4 the highest service (battering) charge, and service projectiles; but, in consequence of the results obtained in recent trials with Pebblepowder, experiments are being carried on to determine the future proof charge.
- 1873, W. Dawson, “Powder Pressures in the First 35-Ton Gun”, in Journal of the Royal United Service Institution, volume 17, number 70, page 4:
  Amd. the official "Extracts of Artillery Proceedings" tell us, 4:3:72, tha the Superintendent, Royal Gun Factories, "proposes tha the proof charge for the 12-inch gun of 35-tons shall be 115 lbs.
- 1897, Sporting Guns and Gunpowders:
  In case barrels sent for proof for the use of nitro powders are intended by the senders to sheet charges of powder or shot greater than the ordinary service charges of the like respective bores set forth in Scale 6, in the said Schedule, then the quantities of powder and shot so intended to be used shall be declared in wwriting, and a proof charge proportionate thereto shall be used.
(electrostatics) A small charge used to test or measure the electric field created by other charges.
- 2021, J. Felipe de Almeida, Maxwell's Equations and the Principles of Electromagnetic Phenomena, pages 3-12:
  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.