WHAT IS A SURGE?

Hawera Star, Volume XLVIII, 19 July 1924, Page 16

WHAT IS A SURGE?

TRANSMISSION LINE PROBLEM.. MARVEL OF PHOTOGRAPHY. The remarkable discovery that electrical disturbances lasting twentybillionths of a second can be made to record themselves on a photographic plate, without light, has been made by Mr. J. F Peters, electrical engineer of the West!nghouse Electric and Manufacturing Company. Photographs made m such an infinitesimal time are most remarkable. To gain an idea of this almost unbelievable speed it is only necessary to point out that light could travel around the earth seven times in one second, and in twenty-billionths of a second it can travel only twenty feet. The. projectile of the monster cannon used bv the-Germans to bombard Paris would have gone in this length of time approximately five-thousandths of an inch —not enough movement to be visible.

The instrument used by Mr. Peters to obtain his photographs is termed a klydonegraph. It consists of a suitable plate-holcler for receiving ordinary photographic plates, and is provided with suitable electrical connections, so that electrical disturbances may ’he brought into contact with the sensitised side of the plate. When surges occur m the transmission line they jihotograph themselves. The surges may last two-billionths of a second, or longer, so that the photographic plates must register them in that minute spaue of time. Mr. Peters states that he has never yet detected visible light in the camera while photograging a surge and that therefore the impulses must contain some property in themselves that affects the plate. The prints obtained from such plate exposures show many geometrical figures of beautiful shapes and also take on ceitain definetc. lorms according to the character of the voltage at the time the surge or impulse occurred. It is possible to observe from the developed plate plate whether the voltage at the time of the surge was positive or negative, whether it was alternating or undirectional and the direction the surge was travelling, and its intensity.

Mr. Peters states that tlie photographs obtained by the Klydonograph are of immense importance to transmission e(ngi)neers. The instrument for taking the photographs is the only practical device yet invented and made for obtaining data in regard to that type of line disturbances known as surges. Heretofore, engineers have only known that surges occur, but where they occur avid their nature has been largely guesswork. The photographic plate now gives the characteristic of surges, thus giving the engineers. data with which to devise line protection.

Tho instrument, Mr Peters states, will do much, to enable the engineering profession to increase the reliability and continuity of service on existing power lines. The device is applicable to transmission lines of all kinds and is connected to them by means of an electrostatic potentiometer. In early tests Mr. Peters used a condenser discharge to simulate the condition that occurs during the period of a surge. From these discharges were obtained his first photographs of electrical impulses. Later, tests were made with the Klydonograph connected directly on a transmission line.