data on an oceanwide basis, and the tempera- 

 ture data will give information on the seasonal 

 changes of the California Current. 



This report presents the original data taken 

 on round-trip voyage 105 of the SS CALI- 

 FORNIAN in November-December 1965. 

 J. F. T. Saur made this trip to check the per- 

 formance of the XBT system and to train the 

 ship's personnel in its operation. The system 

 was subsequently modified by the manufacturer 

 to overcome deficiencies, some of which were 

 diagnosed during this voyage. 



INSTRUMENTATION 



Expendable Bathythermograph System 



The permanent shipboard components of the 

 XBT system are the launcher (fig. 1) and the 

 recorder (fig. 2) along with the connecting 

 electric cables. These components are small 

 enough and light enough to be easily moved 

 from ship to ship. In figure 2, the recorder is 

 shown mounted in a rack with a digitizer- 

 encoder unit. A reperforator unit, which 

 punches digitized data on a five-channel paper 

 tape, is mounted on the top of the rack. Once 

 permanent mounts for the rack have been 

 fixed aboard a ship, the rack can be carried 

 on board by two persons, secured, and checked 

 out in 1 to 2 hours. The expendable component 

 of the system is a canister that contains the 

 expendable probe and wire (fig. 3). 



The sensing element is a rapid-response 

 thermistor wafer which is mounted in the nose 

 of the probe in a manner that allows the water 



Figure 2. — Reading the paper tape punched by the reper- 

 forator on top of the electronic rack which holds the 

 recorder and digitizer encoder unit. 



Figure 1. — Placing an expendable thermograph canister 

 in the loading breech of the launcher. The arrow is 

 pointed at the lower end of the discharge tube. 



Figure 3. — Disassembled canister. The shipboard end of 

 the fine wire pays off the spool (top center) in the 

 canister (center) while the end connected to the therm- 

 istor pays from another spool inside the probe (lower 

 right) through the finned end. Water enters the tube at 

 the tip of the weighted nose of the probe, flows past the 

 thermistor and out through the same orifice as the 

 wire. The cap (left center), removed before loading 

 into the launching tube, provides rubber cushioning to 

 protect the thermistor during shipment and handling. 

 The pin (right center), inserted through the holes in the 

 canister and the hole in one fin of the probe, locks the 

 probe in the canister. When the pin is pulled, the probe 

 is released and slides out of the launch tube by gravity. 



