2 5. OXYGEN- CARBON DIOXIDE SENSING SYSTEM 



This system allows direct reading of the oxygen per- 

 centage inside the sphere. The concentration of carbon 

 dioxide inside the sphere is shown on a second direct- 

 reading dial. This system is similar to the one used in 

 nuclear submarines. This unit can also measure 2 in 

 the water when an external sensor is fitted. 



26. PRESSURE MANIFOLD 



The entire pressure manifolding system has been con- 

 centrated into one panel which includes not only the two 

 direct -reading depth gauges, the shallow gauge and the 

 deep gauge, but also the three pressure transducers for 

 the recording depth gauges. An "aquatap" is fitted to this 

 manifold allowing direct sampling of the water outside the 

 sphere. This special high-pressure valve is fitted with a 

 floating piston such that, if a surge in the line should 

 occur due to breakage of the valve or tubing, the surge 

 check would be pushed shut and the system would be se- 

 cured. The arrangement was tested to 24, 000 psi after 

 installation, and has been successfully used without any 

 sign of leak. 



2 7. AC POWER SUPPLY 



In the past, the ac power supplies for different inves- 

 tigations had to be furnished by the investigator. The 

 bathyscaph now has 1000 watts of 110-115 volt "built-in" 

 ac power available, provided by two solid-state 500-watt 

 inverters permanently inside the sphere. In this way, the 

 scientist has a full choice of power supplies with which to 

 operate his equipment. 



Electrical noise from this and other power units has 

 not yet been eliminated. The main nuisance is high back- 

 ground noise in the underwater telephone circuit. The 

 external cameras and flash units are particularly guilty 

 in this respect. 



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