A New Fall-Rate Equation for T-5 Expendable Bathythermograph (XBT) by TSK (original) (raw)

Abstract

The accuracy of the manufacturer’s fall-rate equation for the T-5 Model of expendable bathythermograph (XBT) has been investigated based on about 300 collocated pairs of XBT-CTD (Conductivity-Temperature-Depth profiler) measurements in various climatological regions. We found that the equation systematically overestimates depth by about 5% for the T-5 produced by Tsurumi Seiki, Co. Ltd. (TSK), but almost no bias is associated with the T-5 produced by Sippican, Inc., in USA. The cause of this difference is not clear, because the two manufacturers’ T-5 probes are reported to have identical shape and weight in water. We propose a new fall-rate equation for the TSK T-5: z(t) = 6.54071_t_ - 0.0018691_t_ 2, where z(t) is depth in meters at time, t, in seconds.

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Authors and Affiliations

1. Department of Geophysics, Graduate School of Science, Tohoku University, Aoba-ku, Sendai, 980-8578, Japan
   Shoichi Kizu & Kimio Hanawa
2. Japan Coast Guard Academy, 5-1 Wakaba-cho, Kure, 737-8512, Japan
   Hiroyuki Yoritaka

Authors

1. Shoichi Kizu
2. Hiroyuki Yoritaka
3. Kimio Hanawa

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Correspondence toShoichi Kizu.

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Kizu, S., Yoritaka, H. & Hanawa, K. A New Fall-Rate Equation for T-5 Expendable Bathythermograph (XBT) by TSK.J Oceanogr 61, 115–121 (2005). https://doi.org/10.1007/s10872-005-0024-4

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• Received: 29 September 2003
• Revised: 10 May 2004
• Accepted: 12 May 2004
• Issue date: February 2005
• DOI: https://doi.org/10.1007/s10872-005-0024-4

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