TABLE III-2 

 Expendable velocimeter prototypes submitted to the Naval Oceanographic Office 



"Expendable Sonic Velocimeter," Dyna Empire, Inc. (Reference 30) 



It is a sing around device operating at about 5000 HZ. 

 It uses one transducer and reflector, four transistors and a 

 single wire, sea return, to lead 16 MA DC power down and -5000 HZ 

 pulses up. The electronic delay is only 20ns or 0.02% of the 

 period. It is planned for use up to 1500 ft depth, free falling 

 with one wire reservoir in the probe and one on the ship. The 

 instrument was tested by the Navy Oceanographic office and a 

 report submitted on January 7, 1965 to the Bureau of Ships. 



According to Table I of that report, the velocity readings 

 taken in one complete temperature cycle during the first 200 hours 

 of submergence show a standard deviation of 0.11 m/s, calculated 

 after subtracting a constant error of 1.4 m/s. This is only 

 about twice the error of the calibration facility, estimated to 

 by 0.05 m/s by the Oceanographic office. The velocimeter was 

 not pressure tested and after 200 hours of submergence the 

 prototype failed. It worked again after it was dried and the 

 exposed wiring coated with epoxy. 



This performance appears to be altogether satisfactory for 

 sonar range prediction. 



33 



Arthur ZH.lUttle.Knr. 



