/ L-. / 



NAVWEPS REPORT 76 50 



—WOTS TP 2675 



COPY 7 fj 



AN INSTRUMENT FOR CONTINUOUS DEEP-SEA 



MEASUREMENT OF VELOCITY OF SOUND, 



TEMPERATURE, AND PRESSURE 



:x^ 



By 



J. R. Lovett 



and 



S. H. Sessions 



Research Department 



ABSTRACT . An electronic instrument for the continuous and con- 

 current measurement in the ocean of velocity of sound, tempera- 

 tuire, and pressure has been designed and tested to depths in 

 excess of 2,000 meters. This 70-pound transistorized instrument 

 contains three sections: a modified NBS velocimeter for measur- 

 ing velocity of sound, a Borg-Warner Vibrotron for pressure, and 

 a WOTS thermistor- controlled Wien-bridge oscillator for tempera- 

 ture. Outputs from the three sections are frequency-modulated 

 signals, mixed for single-conductor cable transmission to the 

 surface. Velocity of sound is transmitted in the band 2,775- 

 5,225 cps, temperature in the band 5jOOO-8,000 cps, and pressure 

 in the band 9 j 712-11,288 cps. Accuracy of measurement is sound 

 velocity 0.5 m/sec, temperature 0.02°C, and pressure I'fo in 

 selected ranges of 0-1,000 and 0-2,000 psi. 



/96/ 



U.S. NAVAL ORDNANCE TEST STATION 

 China Lake, California 



9 Majf' 1961 



