Rg. 9.15 The Dwyer portable carbon dioxide monilor (Mr A P lanuzzr. Naval 

 Facilities Eng Comm ) 



side of the plunger valve. After the sample is 

 pumped through the unit, the plunger valve 

 is released, closing off both the atmospheric 

 vent and the connection to the water satura- 

 tion chamber. The CO2 is absorbed by slowly 

 raising and lowering the absorption basket 

 four times. The indicating tube is then 

 vented to the atmosphere by depressing the 

 vent valve until the fluid level comes to rest, 

 then releasing it. The percent COj is read 

 directly from the position of the fluid level on 

 the calibrated scale. The instrument is reset 

 for a new measurement by depressing both 

 the plunger valve and the vent valve until 

 the fluid is balanced. The unit is zeroed by 

 sliding the scale vertically by means of the 

 zero adjusting nut. 



Several other portable and hand-held de- 

 vices can be used, not only for carbon dioxide 

 monitoring, but for other atmospheric con- 

 taminants as well. DS-2000 carries both a 

 Kitagawa and a Mine Safety Appliances car- 

 bon dioxide testing kit as backup for its 

 primary Dwyer monitoring system. 



Using the pump shown in Figure 9.16, a 

 sample of atmosphere is drawn into a glass 

 phial within which a granular reagent shows 

 concentration of carbon dioxide by color 

 change. Similar in design is a Drager Multi- 

 Gas Detector which, by inserting the proper 

 phials, can measure a wide variety of atmos- 

 pheric trace contaminants. 



Fig 9 16 A Kitagawa CO2 detection kit used as a backup system aboard DS-2000 



Temperature and Humidity: 



In order to avoid the possibility of contami- 

 nation from spilled mercury, only bimetallic 

 temperature sensors are acceptable. A num- 

 ber of vehicles use a relative humidity indi- 

 cator manufactured by the Bacharach In- 

 strument Co. of Pittsburgh, Pa. Both temper- 

 ature and humidity measurements have 

 been combined by Bacharach into one instru- 

 ment with a readout for both variables. In 

 the model used aboard SEA CLIFF and TUR- 

 TLE (Bach. Code 22-4529) temperature is 

 indicated from 0° to 130°F (±1°F accuracy 

 from 32°-130°F) and relative humidity from 

 to 100 percent (±3% accuracy from 15 to 90% 

 RH 32° to 130°F). The design of the tempera- 

 ture sensing element is based on a conven- 

 tional spiral-wound, bimetallic spring con- 

 nected to a pointer. The humidity sensing 

 element consists of a hygroscopic animal 



435 



