C-13 Checking Out the XBT System.— 



After the XBT launcher and recorder are in- 

 stalled and always before beginning an opera- 

 tion aboard ship, the recorder and the launcher 

 to recorder circuit should be checked by per- 

 forming the following steps : 



Step 1. Plug in the recorder power cord to 

 120 VAC (the instrument does not have an 

 On-Off switch). This will cause the red reload 

 indicator signal (A) to light (tig. ( -20). 



Figure C-20. XBT recorder panel. 



Step 2. After a 15-minute warmup period, 

 open the launcher breech and clean contacts, 

 using a clean rag and alcohol. Check the 

 launcher discharge tube for salt deposit, and 

 clean as necessary, using fresh water and a cloth 

 swab. Insert the test canister. NOl'E : Included 

 with each XBT system is a Model A2-A test 

 canister. Its circuit is shown in figure C-21. The 

 test canister should be calibrated every 6 

 months. 



4,700ri±0.l% 

 WW 



■AA/W- 



2l,987nt0.l % 



Figure C-21. Test canister circuit. 



Step 3. Close the breech and lock securely. 

 The reload light will go out, the chart drive will 

 operate for 2 seconds, and the chart stylus (B) 

 will plot 62° F ±0.2° F (1.67° C ±0.1° C) for 

 that period (fig. C-20). The chart drive will 

 then stop, and the green launch light (C) on the 

 left of the temperature scale will go on. NOTE : 

 Check for jitter on the plot and adjust the gain 

 if necessary. 



Step 4. Press and hold the 30°/94° test switch 

 (D) in the 94° position (fig. C-20) for 30 or 40 



seconds. The launch light will go out, the chart 

 drive will start, and the chart stylus will plot 

 94° F ±0.2° F (34.4° C ±0.1° C). 



Step 5. Release the 30°/94° test switch, and 

 press and hold it in the 30° position. Now the 

 stylus will plot 30° F ±0.2° F (-1.1° C ±0.1° 

 C) . Tlie chart paper will advance for 88 seconds 

 ±2 percent, then the chart paper drive will stop 

 and the reload light will go on. 



Step 6. Press and release the recycle switch 

 (E) (fig. C^20). The reload light will go out. 

 The chartr drive will operate for 2 seconds with 

 the chart stylus at 62° F ±0.2° F (16.7° C 

 ±0.1° C). Then the chart drive will stop and 

 the launch light will go on. 



Step 7. Repeat steps 4 and 5 several times to 

 make sure that the chart .stylus is recording tem- 

 peratures within tolerances, that the signal 

 lights are operating properly, and that the chart 

 paper drive advance time (step 5 above) is be- 

 tween 86.2 and 89.8 seconds. When the test 

 switch is changed from the 94° to the 30° po- 

 sition, the stylus should require 1 second for a 

 full scale excursion. Excessive overshoot or 

 sluggishness of movement will require gain ad- 

 justment. If any tolerances are exceeded or any 

 malfunctions are noted, the recorder should be 

 calibrated as described in manual "Instructions 

 for Installation, Operatioia and Maintenance of 

 Sippican Expendable Bathythermograph Sys- 

 tem", and on the NAVOCEANO Planned 

 Maintenance Card (NAVOCEANO 10510/14 

 (5-68)). 



C-14 Recording XBT Data.— XBT data are 

 recorded on the National Oceanographic Data 

 Center Bathythermograph Log NODC-EXP- 

 3167/10 (Rev. 7-68) (fig. C-6). Mechanical 

 BT's and XBT's should be kept on separate BT 

 logs. Instructions for completing the items of 

 the Bathythermograph Log are printed inside 

 the cover of each pad of log sheets. For item 2, 

 consider the XBT chart as a BT slide and num- 

 ber it accordingly. Obtain the sea surface refer- 

 ence temperature in accordance with instruc- 

 tions in paragraph C-5, step 5 "Taking the sea 

 surface reference temperature", or from the 

 ship's injection temperature log. Enter any com- 

 ments concerning the conditions at the time the 

 XBT was taken in the remarks space of the log 

 sheet. Such comments might include: high seas, 

 changing course, wire unspooling improperly, 

 wire fouled on the side of ship, premature part- 

 ing of wire, etc. 



C-15 Deployment of the XBT.— After the 

 XBT system has been chocked out and the ship 

 is coming up on a station, take the XBT by per- 

 forming the following steps. NOTE : One person 

 can take the XBT, however, this requires several 

 trips between recorder and launcher; therefore, 

 if two persons are available one should be sta- 



Change 1—1970 



C-11 



