NYLATRON GS 



STAINLESS 

 STEEL 



EXCITING 



X'FMR 



TOROID 



ALUMINUM 

 ALLOY 



STAINLESS 

 STEEL 



NYLATRON GS 



STAINLESS 

 STEEL 



PICKUP X'FMR 

 TOROID 



MAGNETIC 

 SHIELDING 

 FOIL, 2 LAYERS 



SILICONE 

 RUBBER FOAM 



EPOXY 

 RESIN 



THERMISTOR 



EPOXY 

 RESIN 



Fig. 7- Probe construction details. 



less steel legs of the instrument. Holes drilled 

 through the leg allow free circulation of water 

 past the thermistor. The legs were designed to 

 crush or shear upon severe impact without 

 destroying the watertight integrity of the free- 

 swimming vehicle. 



The instrument was proof pressure tested at 

 3,000 psi which corresponds to a depth of 

 approximately 6,800 feet. The instrument was 

 also cycled repeatedly between normal atmospheric 

 pressure and 2,000 psi without ill effect. 



POWER SUPPLY 



In the original application the conductivity 

 cell was excited by a 320 cps power supply. 

 This power supply could be constructed to operate 

 the conductivity cell at 1+00 cps to power stand- 

 ard servo components for automatic null balancing. 

 Fig. 8 shows the power supply with the outer 

 housing removed. This rugged compact unit con- 

 sists of a transistorized audio amplifier driven 

 by an enclosed tuning fork oscillator. 



15 



