Depth, 

 m 







Temperature Difference, °C 







6C 



9C 



lie 



12C 



13C 



16C 



17C 



200 



-0.25 



0.03 



0.17 



0.13 



0.09 



-0.31 



-0.12 



250 



0.00 



0.21 



0.25 



0.28 



0.28 



0.15 



0.47 



300 



0.02 



0.01 



0.15 



0.53 



0.30 



0.18 



0.35 



400 



-0.07 



-0.22 



-0.09 



-0.13 



-0.06 



-0.28 



0.18 



500 



-0.06 



-0.17 



-0.06 



-0.21 



-0.17 



-0.26 



0.06 



600 



-0.09 



-0.12 



-0.12 



-0.22 



-0.15 



-0.17 



0.06 



800 



-0.11 



0.15 



- 



-0.14 



-0.12 



- 



0.01 



1000 



- 



0.63 



- 



-0.07 



-0.17 



- 



-0.01 



1200 



- 



0.51 



- 



0.45 



-0.15 



- 



- 



1500 



- 



0.38 



- 



0.36 



-0.07 



- 



- 



Table 42. Comparison of 1830-m RAPLOC/DEEPTOW XBT profiles classified 

 as catastrophic failures with average CTD/SV temperatures. 



indication of insulation failure in the upper 50 m. An inspection of the differences listed 

 in table 42 shows that XBT 9C and XBT 1 2C measured temperatures at 1 200 and 1 500 m 

 that were considerably higher than the CTD/SV temperatures. For the remaining five 

 XBT profiles, the differences were within ±0.24°C of the average CTD/SV temperatures 

 for 28 (75.9%) of 37 comparisons. Thus it appears that the accuracy of temperature 

 measurements made at depths greater than the first indication of insulation failure are 

 questionable — sometimes they may be accurate and sometimes they may be inaccurate. 



Of the seven profiles finally classified as partial successes, all had one or more 

 "glitches" at depths greater than 50 m and less than 1830 m. Figure 40, a copy of XBT 

 19C, is an example of such a profile. Small "glitches" are observed at depths of 90, 560, 

 610, and 1010 m. In spite of the indications of insulation failure, the profile appears to 

 record acceptable temperatures to the maximum depth. Profile 19C was finally classified 

 as a partial success since the recorded temperatures are suspect for depths greater than 90 m, 

 the depth of the first indication of insulation failure. Table 43 hsts, for depths greater than 

 200 m, the differences for the profiles finally classified as partial successes. Also shown 

 for each profile is the depth of the first "glitch". 



Thus, for this set of measurements, it is concluded that the use of measurements 

 made by probes exhibiting an apparent temporary insulation failure depends upon the 

 importance of the measurement in a particular appHcation. However, if the measurements 

 are used for depths greater than the first indication of insulation failure, the accuracy of 

 the measurements should be suspect. 



Since no independent temperature measurements were made concurrent with the 

 FLIP XBT measurements, an analysis of their accuracy is not possible. Of the eight profiles 

 made by the FLIP, one was classified as a catastrophic failure since it recorded a "glitch" 

 at 29 m. The remaining seven were classified as successes since they were visually accept- 

 able to the maximum depth of 1830 m. An intercomparison of these seven profiles showed 

 that XBT 2F recorded temperatures for depths greater than 250 m were consistently lower 



100 



