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UNDERWATER WEATHER STATION 



Fig. 139- Aquanaut Murray holds the upper 

 (right) and lower (left) current meter pack- 

 ages prior to installation 



Several light sources for the current meter were tested during its development. The final 

 design incorporated a CM-8 series bulb manufactured by the Chicago Miniature Lamp Works. 

 The bulb, because of its small size, was capable of withstanding the high pressure of the en- 

 vironment and proved to be less susceptible to marine growth than larger lamps which were 

 tested. 



Direction of current flow was indicated by a Cycolac vane mounted on sapphire pivots and 

 housed axially with the Savonius rotor. Vane position was sensed electrically by a potentiom- 

 eter, and its analog readout appeared inside Sealab. A magnet was attached to the potentiom- 

 eter shaft and the unit sealed in an oil-filled canister. A second magnet fastened to the edge 

 of the vane provided magnetic coupling of vane rotation with potentiometer rotation. The oil 

 damping reduced overswing of the potentiometer during fast transitions. 



Vibrotron Pressure Sensor 



The Vibrotron is a vibrating-wire transducer which converts absolute pressure input to 

 an output signal with a frequency inversely proportional to the applied pressure. It was chosen 

 for use at the sea-floor weather station because of its ability to resolve small changes in ab- 

 solute pressure while in a very-high-pressure environment. Excitation and signal amplification 

 electronic circuitry was modularized and housed with the transducer in an oil-filled canister. 

 The audio output signal was telemetered directly to the data acquisition system on shore where 

 the frequency variations were digitized and recorded on magnetic tape along with the other 

 measured parameters. 



