Figure R-2. — Sonar pinger bottom positioning technique 

 for Nansen cast bottom temperature measurements. 



ADP (Ammonium di-hydrogen phosphate) 

 crystals mounted in parallel on a backing plate. 

 To achieve good acoustic coupling with the 

 water, the aluminum transducer housing is filled 

 with dehydrated castor oil and is closed with a 

 special rubber diaphragm. In addition to the 

 pinger, a hydrophone and its amplifiers (or echo 

 sounding equipment used in the passive man- 



ner), paper-chart recorders, and a triggered- 

 sweep oscilloscope are required in the Sonar 

 pinger operation to receive and visually or 

 graphically display the pinger signal. 



R-3 Assmbling Rack and Mounting Sonar 

 Pinger. — The Sonar pinger is mounted on a 

 Unistrut (a registered trade name) pinger rack. 

 See chapter N for Sonar pinger mounting for 

 deep sea photography. The parts of the pinger 

 rack are listed and described in table R-1. 



Table R^l. Unistrut pinger rack parts 



The assembled pinger rack is illustrated in 

 figure R-6. 



TRANSFORMER 

 CONNECTIONS 



END CAP 



MAIN DRIVER 

 CIRCUITRY 



Figure R-3. The pinger driver disassembled. 



R-2 



