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A device for obtaining a record of temperature against depth (actually, pressure) in the ocean from a ship underway. Abbreviated BT. Also known as bathythermosphere.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.



an instrument lowered from a ship in motion for measuring the distribution of the temperature of water relative to depth. The body of a bathythermograph has a streamlined shape and is equipped with tail fins for stabilizing the instrument’s attitude when it is lowered into the water; the instrument is lowered by means of a steel cable.

The temperature sensor is a hot-wire anemometer, consisting of a long copper capillary tube mounted on the tail fins. One end of the capillary tube is sealed and the other is connected to the fixed end of a manometric coil spring. The capillary and spring are filled with toluene. When the temperature changes, the volume of toluene and, consequently, the pressure within the manometric system change. With an increase in temperature the free end of the manometric spring is untwisted at an angle proportional to the amount of temperature change, and it is twisted with a decrease in temperature. The pointer attached to the free end of the manometric spring records the temperature on a smoked-glass plate, which is shifted by a hydrostatic depth sensor as the instrument is lowered in the water. Hermetically sealed Sylphons function as the depth sensors. Modern bathythermographs record water temperature with a minimum accuracy of 0.1°C. They are used in oceanographic research and on fishing survey vessels.


Rukovodstvo po gidrologicheskim rabotam v okeanakh i moriakh. Leningrad, 1967.
Deriugin, K. K., and I. A. Stepaniuk. Morskaia gidrometriia. Leningrad, 1974.
The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
Based on in-depth studies, recommendations for correcting biases in expendable bathythermograph (XBT) data are presented, and the implications for applications and ongoing research to improve the quality of future XBT data are discussed.
Other WP-3D flight tracks focused on the large-scale environmental conditions, including water vapor, temperature, and winds from transects between the island and ship sites (Kerns and Chen 2014b); the coupled atmosphere--ocean boundary layers; convectively generated cold pools and air--sea fluxes using the global positioning system (GPS) dropsondes; the airborne expendable bathythermographs (AXBTs); and the downward-looking infrared (IR) imaging spectrometer called the Japanese Dynamic Earth Observation by Very Long Baseline Interferometer (JADE) (Table ESI).
There are two other published time series estimates of the MHT in the Atlantic that are being maintained: At 35[degrees]S in the South Atlantic MHT has been estimated using a combination of expendable bathythermograph (XBT) data and Argo profiling floats (Garzoli et al.
At 35[degrees]S in the South Atlantic, MHT has been estimated using a combination of expendable bathythermograph (XBT) data and Argo profiling floats (Garzoli et al.
The sailors received the awards for overhauling the AM-3729/SR amplifiers, LS-474/U speakers, Type G telephones, AN/BQH bathythermographs and electrical workbenches aboard Eisenhower, rather than sending them to contractors for overhaul or purchasing new equipment.
Like all ships of her class, the Mary Sears has a length of 329 feet and a displacement of 4,700 tons, and she carries the latest in over-the-side sensors and sampling equipment, including bathythermographs, bottom corers and seismic equipment.
Water column data were collected with conductivity-temperature-depth (CTD) profilers 1 h before sunrise and 1 h after sunset on each survey day and with expendable bathythermographs (XBTs) during daylight hours at intervals of ~55 km.
They built instruments (bathythermographs) to measure these changes and trained sailors to use them to avoid detection from sonar, which "saved many of our ships," the Navy reported.
Though no airborne expendable bathythermographs were deployed, ocean conditions were measured by several Argo profiling floats (e.g., Roemmich et al.
Water temperature and depth profiles were collected at each station by using bathythermographs attached to the headrope of the bottom trawl net (expendable models before 1993 and microbathythermographs in later years).
For Joaquin, subsurface ocean observations were obtained through deployment of Airborne Expendable Bathythermographs (AXBTs) and Air Launched Autonomous Micro Observer (ALAMO) profiling floats as part of the TROPIC field program.
The P-3 also carried a downward-looking ocean wave radar, a downward-looking W-band Doppler cloud radar, and airborne expendable bathythermographs (AXBTs) from the navy to measure the ocean mixed layer.