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Autor
, EDITORIAL
Institución
Resumen
IN THE FOLLOWING LINES A METHOD FOR COUPLING A SEISMOMETER TOA RECORDING GALVANOMETER BY MEANS OF A PHOTOELECTRIC CELL AND A LINEAR AMPLIFIER IS PRESENTED. THE THEORY SHOWS THAT SUCH A SYSTEM OPERATES AS IF THE RECORDER WERE MECHANICALLY COUPLED TO THE SEISMOMETER, I . E ., THE RESPONSE IS PRACTICALLY LINEAR. THE PURPOSE OF THE INSTRUMENT IS TO RECOR ON SMOKED PAPER IN SUCH A WAY THAT FRICTION OF THE STYLUS IS PRACTICALLY OVERCOME BY THE FINAL AMPLIFIER CURRENT AND NO EFFECT ON THE PENDULUM ITSELF IS PRESENT, SO THE SEISMOMETER BEHAVES PRACTICALLY AS A PHOGRAPHIC PENDULUM WITH THE ADDED ADVANTAGE OF CHEAP OPERATION. THE RECORDER ITSELF MAY BE INSTALLED IN ANY CONVENIENT PLACE WHERE THE RECORD IS VISIBLE ALL THE TIME. THE APPARATUS CAN BE BUILT IN ANY MECHANICAL SHOP AND THE PRINCIPLE MAY BE SUCCESSFULLY APPLIED TO REGISTER ON SMOKED PAPER ANY PHENOMENON WHICH MAY BE MEASURED BY MEANS OF A ROTATION OR TORSION, SUCH AS IS PROVIDED BY THE DEFLECTIONS OF A GALVANOMETER COIL OR ROTATING MIRROR. MAGNIFICATIONS OF HE ORDER OF 3,000 TO 5,000 ARE EASILY OBTAINED.