Fig, 9 13 Bio Marine Industries automatic oxygen flow control and sensor unit (Bio 

 Manne. Ind ) 



Fig, 9,14 Westinghouse-Krasberg oxygen monitor (Mr A P lanuzzi, Naval Facili- 

 ties Eng Comm,} 



Other oxygen analyzing devices are com- 

 mercially available from Beckman, Teledyne 

 Analytical Instruments, Johnson-Williams 

 and others. In some vehicles a second device 

 is sometimes carried as a backup in the 

 event of a malfunction in the primary device. 



Carbon Dioxide: 



Monitors for detecting carbon dioxide 

 range from the complex to the very simple. 

 The U.S. Navy's SEA CUFF and TURTLE 

 carry both a fixed and a portable carbon 

 dioxide monitoring device. The fixed moni- 

 toring device is manufactured by Interna- 

 tional Gas Detector Ltd. and reads from 0-5 

 percent with an accuracy of ±0.25 percent. 

 The analyzer contains two sealed chambers, 

 each connected to one end of a nonspillable 

 liquid manometer tube. One of the chambers 

 contains a cartridge of soda lime, the other 

 contains a dummy, or inert, cartridge. At- 

 mosphere diffuses into the chambers 

 through porous rings. The soda lime absorbs 

 carbon dioxide creating a lower pressure in 

 its side of the manometer and drawing the 

 liquid up in that leg of the tube. The percent 

 of carbon dioxide in the sample is read di- 

 rectly on a O-to-5 percent scale behind the 

 tube. A knob on the top of the unit is used to 

 move the scale up and down behind the tube 

 to zero the unit before use. Each chamber 

 contains a small cartridge of cotton wool 

 soaked with water to maintain equal vapor 

 pressures in each side of the unit, thereby 

 making it impervious to changes in humid- 

 ity. 



The portable analyzer is shown in Figure 

 9.15. It uses a liquid absorbent to remove 

 carbon dioxide and indicates concentration 

 by volume change. The unit is manufactured 

 by F. W. Dwyer Company and is found in a 

 number of submersibles. In operation, an 

 aspirator bulb is used to force the air sample 

 into the water saturation chamber through 

 the sample line. The plunger valve is de- 

 pressed while the aspirator pumps the sam- 

 ple in, thereby allowing the sample to pass 

 down through the sample intake tube, out 

 through the cross bores at the bottom of the 

 intake tube, up through the distilled water in 

 the water saturation chamber and over into 

 the sample chamber. The sample is vented 

 off to the atmosphere through a float on one 



434 



