An Expendable Bathythermograph (XBT) is a small, single-use probe that can be deployed from RV Investigator while underway.

What it's used for

Hand-held launcher for XBT instrument.

The XBT captures temperature data as it moves through the water. It provides a quick and inexpensive means for obtaining a record of temperature as a function of depth in the ocean.

How it works

The XBT is a hand-held device that consists of an expendable probe, a data processing and recording system, and a launcher.

When the XBT probe is launched, the copper wire connecting the probe and launcher unwinds as it descends through the water. Once the electrode in the probe makes contact with the water, temperature data can be transmitted back to the ship's data processing equipment.

Data collected by the XBT can be used in conjunction with other recording equipment - for example, a thermosalinograph - to profile the water column.