GB161988A - Improved method of and apparatus for depth sounding - Google Patents

Abstract

161,988. Blondel, A. April 21, 1920, [Convention date]. Determining distances acoustically; sound, actuating apparatus by; detecting subaqueous sounds.-In sea-sounding by the echo method separate receivers, or separate circuits with one receiver, are used for the initial sound and the echo, the " echo " circuit being incomplete or shunted till after the emission of the sound and the " time of flight " of the sound is measured bv the amount a condenser is charged which is in a circuit made when the initial sound is received and broken by the echo. The receivers are placed on a ship, say at the end of water-filled passages separated by diaphragms from the sea, but Fig. 2<bis> illustrates the use of one receiver M with two circuits. Closing the switch u discharges the bomb A and gives a record C,. At the same time the ' echo ' circuit is completed by a relay at R1 so that the echo can be recorded as C2. In the modification shown in Fig. 5, an insulating and a conducting drum K1 and K<1>1 rotate side by side, one carrying a conducting strip d<1> and the other an insulating strip d<1>1 so arranged that the ' echo ' circuit is cut when the bomb discharge circuit is complete. If, instead of the recorders G1, G2 with marking arms A1, A2, relays 3 and 4, Fig. 8, are used, an armature 15 can be attracted when the initial sound is received to complete a circuit which is broken when the echo relay 4 pulls over the armature 19. During the time current flows from the battery B0, a condenser C is charged, the amount of charge being ascertained by means of an electrometer E or ballistic galvonometer H so that a measure of the ' time of flight ' of the sound is obtained. Specification 22940/14 is referred to.